Wszystkie pola: 75.75.-c - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Nonlinear Zeeman Splitting of Holes in Doped GaAs Heterostructures
Autorzy:: Kubisa, M.
Ryczko, K.
Jadczak, J.
Bryja, L.
Misiewicz, J.
Potemski, M.
Powiązania:: https://bibliotekanauki.pl/articles/2047934.pdf
Data publikacji:: 2011-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
Opis:: Polarization-resolved photoluminescence from two-dimensional GaAs/GaAlAs heterostructures doped with acceptors was studied in high magnetic fields. Measurements were carried out in low temperatures up to 2 K and magnetic field up to 21 T. Experiments performed in the Faraday configuration enabled to resolve hole states with different spin orientation. We observed a nonlinear behavior of valence-band g factor in strong magnetic fields. To explain obtained results, a detailed theoretical calculation was carried out based on the Luttinger model for valence-band states. We examined the spin splitting of hole levels under the influence of both external magnetic field and built-in electric field existing in doped heterostructures. Changes of hole g factor with the width of the structure and the density of two-dimensional carriers are discussed.
Źródło:: Acta Physica Polonica A; 2011, 119, 5; 609-611
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Transport and Thermoelectric Properties of Magnetic Organic Structures
Autorzy:: Zberecki, K.
Świrkowicz, R.
Powiązania:: https://bibliotekanauki.pl/articles/1030828.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.63.-b
75.75.-c
Opis:: Using ab initio methods, we study transport and thermoelectric phenomena of magnetic organic chains functionalized with nitroxide groups. We predict very good thermoelectric performance of the structure, as the conventional and spin Seebeck coefficients are remarkably enhanced. Our results suggest that magnetic organic chains would have a great potential for applications in spintronic devices.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 532-534
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Thermoelectric Properties of Doped Zigzag Silicene Nanoribbons
Autorzy:: Zberecki, K.
Swirkowicz, R.
Barnaś, J.
Powiązania:: https://bibliotekanauki.pl/articles/1386845.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.63.-b
75.75.-c
Opis:: Thermoelectric properties of silicene nanoribbons doped with magnetic impurity atoms are investigated theoretically for both antiparallel and parallel orientations of the edge magnetic moments. Spin density distribution and transport parameters have been determined by ab-initio numerical methods based on the density functional theory. Doping with magnetic atoms considerably modifies the spin density distribution, leading to a ground state with a non-zero magnetic moment. Apart from this, the spin thermopower can be considerably enhanced by the impurity atoms.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 505-507
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Electron Mediated Mn-Mn Interaction in Quantum Dots
Autorzy:: Bak, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1428517.pdf
Data publikacji:: 2012-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.85.+t
85.75.-d
Opis:: We present a theoretical study of magnetic interaction in quantum dots with magnetic $Mn^{2+}$ in dot impurities. We show that gate voltage applied to the quantum dot shifts the centers of electron clouds. Exact formulae for the perturbed spin density allow us to derive expression for the change of the strength of the sp-d coupling. Estimations show that sp-d exchange integral is very sensitive to the gate voltage variations. Exact formulae for the change of the effective exchange integrals are derived. As the spin coded qubits are elements of the RAM memory, a part of the energy stored in magnetic coupling will be dissipated when information is written or erased. We estimate this energy and find it sufficiently large to destroy quantum coherence during quantum computing. Finally, we discuss the interdot spin coupling and show the effect of gate voltage operations on the spin intra- and interdot Ruderman-Kittel-Kasuya-Yosida coupling.
Źródło:: Acta Physica Polonica A; 2012, 121, 5-6; 1219-1221
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Magnetization Reversal Processes in Nanocrystalline (Pr, Dy)-(Fe, Co)-B Bulk Alloys
Autorzy:: Przybył, A.
Pawlik, K.
Pawlik, P.
Gębara, P.
Wysłocki, J.
Powiązania:: https://bibliotekanauki.pl/articles/1387335.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.20.En
75.75.-c
75.75.Cd
Opis:: The aim of this paper was to study the phase constitution, magnetic properties and magnetization reversal processes in the rapidly solidified bulk (Pr,Dy)-(Fe,Co)-B alloys doped with Zr, Ti, Mn and Ni. The 3 mm outer diameter tubes samples of the $Pr₈Dy₁Fe₆₀Co₇Ni_{(6x)}MnₓB₁₄Zr₁Ti₃$ (where x = 0, 3, 6) alloys were produced by suction-casting technique. The admixture of Zr was introduced in order to improve their glass forming abilities while Dy was substituted to enhance the magnetocrystalline anisotropy of hard magnetic phase. The effect of Ni and Mn addition on the phase constitution and magnetic properties was studied in the presented work.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 579-581
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Normal Modes in a Linear Chain of Nanomagnets
Autorzy:: Wal, A.
Dubiel, Ł.
Powiązania:: https://bibliotekanauki.pl/articles/1032392.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.75.Jn
71.70.Gm
Opis:: The dynamics of magnetization in low-dimensional systems of micromagnets has been a very interesting subject of scientific studies last years. Excitations in such systems may have forms of normal modes. The frequency of the mode can be determined with the use of analytical methods as well as of micromagnetic numerical techniques. One of the latter is the Hamiltonian dynamical matrix method. The method is an analogue of that used to determine oscillations of atoms in crystal. The advantage of it is the possibility of calculating both of all frequencies and profiles of normal modes. Excitations in a finite system can depend on the size of it, as was noticed by experimentalists. The aim of this study is an analysis of eigenstates of the chain consisting of finite numbers of nanomagnets and dependence of states on orientation of magnetic moments and external magnetic field.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 100-102
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Spin-wave Instability Theory for Ferromagnetic Nanostructures
Autorzy:: Haghshenasfard, Z.
Nguyen, H.
Cottam, M.
Powiązania:: https://bibliotekanauki.pl/articles/1189207.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Ds
75.75.-c
75.78.-n
Opis:: A microscopic, or Hamiltonian-based, theory is outlined for studying the spin-wave instability thresholds of the parametric processes occurring in ferromagnetic nanostructures under conditions of pumping with a microwave field. Most previous work has concentrated on spheres or films with dimensions of order several μm or more, with the theoretical interpretation being made in terms of macroscopic (or continuum) methods. At smaller length scales, as in ultrathin films and nanowires with thickness or lateral dimensions less than about 100 nm, the discreteness of the quantized spin waves and their spatial distributions become modified, making it more appropriate to employ a microscopic approach to the nonlinear dynamics with a lattice of effective spins interacting through the magnetic dipole-dipole and exchange interactions. Effects of microwave pumping (in either the parallel or perpendicular configuration) are incorporated in calculations for the instability thresholds of the quantized spin-wave bands in different nanostructures and materials.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 192-197
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Monte Carlo Simulations of Ferromagnetic Nanocomposites
Autorzy:: Woińska, M.
Majhofer, A.
Gosk, J.
Szczytko, J.
Powiązania:: https://bibliotekanauki.pl/articles/1403635.pdf
Data publikacji:: 2012-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Mg
75.50.Tt
75.75.-c
Opis:: We present results of Monte Carlo simulations of a model system of Co nanoparticles in an external magnetic field. In our simulations we take into account the interaction with the external magnetic field, the energy of crystallographic anisotropy and the dipole-dipole interactions between single domain nanoparticles. We apply the standard Metropolis algorithm to a cluster of 27 randomly distributed superparamagnetic Co nanoparticles. We investigate the dependence of blocking temperature $T_{B}$ on particle and cluster size.
Źródło:: Acta Physica Polonica A; 2012, 122, 6; 1019-1021
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Low-Temperature Magnetic Properties of Nanocomposites Containing Superparamagnetic $Fe_3C$ Particles
Autorzy:: David, B.
Schneeweiss, O.
Šantavá, E.
Morjan, I.
Powiązania:: https://bibliotekanauki.pl/articles/1507060.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.07.Wx
75.50.Bb
75.75.-c
Opis:: Two nanopowders containing superparamagnetic $Fe_3C$ particles, superparamagnetic $Fe_3O_4//γ-Fe_2O_3$ particles and carbon black phase were synthesised by the method of laser-induced homogeneous pyrolysis of gaseous precursors. Both were characterised by X-ray diffraction, Mössbauer spectrometry and standard magnetic measurements. The mean crystallite size of $Fe_3C$ was 3 nm for the first sample and 10 nm for the second sample. Mössbauer spectra measured at 27 K and zero-field cooled/field cooled curves measured down to 4 K are reported.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 766-767
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Indirect Coupling Between Localized Magnetic Moments in Zero-Dimensional Graphene Nanostructures (Quantum Dots)
Autorzy:: Szałowski, K.
Powiązania:: https://bibliotekanauki.pl/articles/1201877.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Hx
75.75.-c
73.22.Pr
Opis:: The indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling between on-site magnetic impurities is studied for two kinds of graphene nanoflakes consisting of approximately 100 carbon atoms, posessing either zigzag or armchair edge. The tight-binding Hamiltonian with Hubbard term is used in non-perturbative calculations of coupling between the impurities, placed at the edge of the structure. In general, for zigzag-edged nanoflakes a pronounced coupling robust against charge doping is found, while for armchair-edged structures the interaction is weaker and much more sensitive to charge doping. Also the distance dependence of indirect exchange differs significantly for both edge forms.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 236-237
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: In-Plane Edge Magnetism in Graphene-Like Nanoribbons
Autorzy:: Krompiewski, S.
Cuniberti, G.
Powiązania:: https://bibliotekanauki.pl/articles/1032763.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.30.Gw
61.48.Gh
Opis:: This paper is devoted to identification of the most important factors responsible for formation of magnetic moments at edges of graphene-like nanoribbons. The main role is attributed to the Hubbard correlations (within unrestricted Hartree-Fock approximation) and intrinsic spin-orbit interactions, but additionally a perpendicular electric field is also taken into account. Of particular interest is the interplay of the in-plane edge magnetism and the energy band gap. It is shown that, with the increasing electric field, typically the following phases develop: magnetic insulator (with in-plane spins), nonmagnetic narrow-band semiconductor, and nonmagnetic band insulator.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 828-829
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Spin Glass Dynamics of Nanoparticle $La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3$ Obtained by a Mechanochemical Milling
Autorzy:: Perovic, M.
Mrakovic, A.
Kusigerski, V.
Blanusa, J.
Spasojevic, V.
Powiązania:: https://bibliotekanauki.pl/articles/1534032.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.75.Jn
75.50.Lk
Opis:: Spin dynamics of nanoparticle $La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3$ system was studied through the set of diverse magnetic measurements. Analysis of the data obtained from magnetic relaxation measurements, memory effect and AC susceptibility experiments pointed to a spin glass like behavior of interacting nanoparticle system.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 813-814
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Accents in Modern High Saturation Nanocrystalline Fe-Rich Alloys
Autorzy:: Butvinová, B.
Butvin, P.
Maťko, I.
Janičkovič, D.
Kuzminski, M.
Ślawska-Waniewska, A.
Švec, P.
Chromčíková, M.
Powiązania:: https://bibliotekanauki.pl/articles/1030276.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Bb
75.60.-d
75.75.-c
Opis:: Post processing limits for iron-rich Fe-Cu-Si-B-P high-induction rapidly-quenched ribbons have been tested. 530°C/20 min is already too much, formed borides being the essential culprit of magnetic properties deterioration. Unlike standard Si-poor Fe-Nb-Cu-B-Si Finemets, these alloys annealed even in "technical" Ar below the upper limit do not create significant squeezing surfaces.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 711-713
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Magnetic properties of hexagonal graphene nanomeshes
Autorzy:: Zwierzycki, M.
Ryndyk, D.
Powiązania:: https://bibliotekanauki.pl/articles/1054780.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.22.Pr
75.75.-c
72.25.Dc
Opis:: Graphene nanomeshes are the nanostructures consisting of graphene flake with a regular pattern of antidots (holes) punched through it. Thanks to the energy gaps opening in electronic spectrum, nanomesh-based transistors offer improved I_{on}/I_{off} ratio of the collector current while supporting up to 100 larger driving currents than nanoribbon-based devices. In this paper the electronic and magnetic structure of graphene nanomeshes with hexagonally shaped antidots was studied. It has been found that the internal zigzag edges support magnetic moments and that lowest energy magnetic configuration is antiferromagnetic. The density of states calculated for ground state configuration exhibit the energy gap which can be substantially reduced upon switching (e.g. by external magnetic field) to ferromagnetic configuration. Based on this we predict that the structure will exhibit magnetoresistive effect, which makes graphene nanomeshes of this kind relevant for spintronic applications.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 830-832
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Effect of the sign of anisotropy constants on the properties of the system of interacting ferromagnetic nanoparticles
Autorzy:: Sadek, M.
Marchwiany, M.
Woinska, M.
Majhofer, A.
Gosk, J.
Twardowski, A.
Szczytko, J.
Powiązania:: https://bibliotekanauki.pl/articles/1159850.pdf
Data publikacji:: 2016-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Mg
75.50.Tt
75.75.-c
Opis:: We use the Monte Carlo simulation method to investigate the influence of the signs of magnetocrystalline anisotropy constants and the magnetic dipole-dipole interactions on the zero field cooled-field cooled magnetization experiments and hysteresis curves of a system of magnetic nanoparticles. Positive first cubic anisotropy constant K₁ results in larger blocking temperatures and larger coercive fields of a system, while the second anisotropy constant K₂ is practically of negligible importance for the phenomena investigated. Magnetic dipole-dipole interactions are important only in the most dense systems of particles and their effects practically disappear for systems where the distance between the closest particles exceeds three particle diameters.
Źródło:: Acta Physica Polonica A; 2016, 129, 1a; A-53-A-55
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 16.

Tytuł:: Structural and Thermophysical Properties of Magnetic Beads Containing Metallic Nanocrystallites
Autorzy:: Izydorzak, M.
Leonowicz, M.
Skumiel, A.
Powiązania:: https://bibliotekanauki.pl/articles/1490752.pdf
Data publikacji:: 2012-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Bb
75.75.-c
81.07.-b
Opis:: Cobalt, iron, nickel and iron carbide nanocrystallites, stabilized within carbon beads, were prepared by the three-step procedure including formation of metal acrylamide complex, followed by frontal polymerization and pyrolysis of the polymer at various temperatures. The beads containing the nanocrystallites exhibit domination of the ferromagnetic ordering. The analysis of calorimetric results allowed estimation of the efficiency of the hyperthermal effect, under the influence of an alternating magnetic field. The XTT tests show that the extracts prepared on the basis of the $Fe_3C$ containing beads are nontoxic, whereas these made of the composites containing Co and Ni exhibit negligible cytotoxicity for the test article/vehicle ratios 6.25 and 3.125 mg/ml.
Źródło:: Acta Physica Polonica A; 2012, 121, 1; 68-70
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 17.

Tytuł:: Influence of Nb Addition on Magnetic Properties of the Nanocrystalline $(Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ$ (where x = 1, 2, 4) Alloy Ribbons
Autorzy:: Szwaja, M.
Pawlik, K.
Pawlik, P.
Gębara, P.
Michalski, B.
Powiązania:: https://bibliotekanauki.pl/articles/1387907.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.20.En
75.75.-c
75.75.Cd
Opis:: In the present work the magnetic properties and phase constitution of $(Nd₁₀Fe₆₇B₂₃)_{100-x}Nbₓ$ (where x = 1, 2, 4) alloys in the form of ribbons were investigated. The base alloys were prepared by arc-melting the high purity elements with pre-alloyed Fe-B under an Ar atmosphere. The ribbon samples were obtained by controlled atmosphere melt-spinning technique. In order to generate the nanocrystalline microstructure and hard magnetic properties, samples were annealed at various temperatures (from 923 K to 1023 K) for 5 min. The aim of the present work was to determine the influence of Nb admixture and annealing conditions on the phase constitution and magnetic properties.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 623-625
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 18.

Tytuł:: Magnetic Behaviour of Ferritin Nanoparticles
Autorzy:: Miglierini, M.
Lancok, A.
Powiązania:: https://bibliotekanauki.pl/articles/1534808.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.80.+y
31.30.Gs
75.75.-c
Opis:: Characterization of magnetic behaviour of ferritin nanoparticles of biological origin is presented. Two types of samples prepared from human and horse spleen tissues were investigated by $\text{}^{57}Fe$ Mössbauer spectrometry. At room temperature, ferritin nanoparticles exhibit superparamagnetic behaviour due to their small dimensions. First occurrence of magnetic interactions was noticed below 60 K. Blocking temperature of human and horse ferritin nanoparticles was determined to be of 16 K and 32 K, respectively.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 944-945
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 19.

Tytuł:: Effect of Mechanochemical Treatment on Magnetic Properties of Nanodimensional Magnetite-Type Materials
Autorzy:: Cherkezova-Zheleva, Z.
Zaharieva, K.
Buchkov, K.
Blagoev, B.
Mitov, I.
Powiązania:: https://bibliotekanauki.pl/articles/1382568.pdf
Data publikacji:: 2014-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.60.-d
75.75.-c
82.80.Ej
Opis:: The presented study compares magnetic properties of Ni-doped magnetites $Ni_{0.5}^{2+}Fe_{0.5}^{2+}Fe_{2}^{3+}O_{4}$ to magnetite $(Fe_3O_4)$ sample. Physicochemical properties of materials were registered by means of X-ray powder diffraction, Mössbauer spectroscopy, saturation magnetization and physical properties measurement systems. It was obtained that used preparation procedures lead to synthesis of single phase spinel materials with close nanodimensional size about 8-12 nm. Mechanochemically synthesized sample shows better magnetic properties as lower blocking temperature of superparamagnetic state and minimal coercivity in comparison to other studied materials.
Źródło:: Acta Physica Polonica A; 2014, 126, 4; 912-915
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 20.

Tytuł:: Magnetoresistance of Electrochemically Produced NiFe and CoNiFe Nanowires
Autorzy:: Avcu, D.
Atalay, F.
Aydogmus, E.
Kaya, H.
Atalay, S.
Powiązania:: https://bibliotekanauki.pl/articles/1215584.pdf
Data publikacji:: 2014-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.07.Gf
81.15.Pq
75.75.-c
Opis:: CoNiFe and NiFe nanowires were electrochemically produced by dc electrodeposition on highly ordered porous anodic alumina oxide templates. Scanning electron microscope images of nanowires after removing the alumina membrane showed that these nanowires are uniform with the diameters of about 220-300 nm and about 25-30 μm length. The energy dispersive X-ray analysis showed that the composition of the nanowires is $Ni_{88}Fe_{12}$, $Co_7Ni_{82}Fe_{11}$. Magnetic field was applied by an electromagnet and resistance was measured by four point technique.
Źródło:: Acta Physica Polonica A; 2014, 125, 2; 230-231
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 21.

Tytuł:: Magnetic Properties of "As-Prepared" and Chemically Modified Multiwalled Carbon Nanotubes
Autorzy:: Kuryliszyn-Kudelska, I.
Małolepszy, A.
Mazurkiewicz, M.
Stobinski, L.
Dobrowolski, W.
Powiązania:: https://bibliotekanauki.pl/articles/2047920.pdf
Data publikacji:: 2011-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.48.De
81.20.Ym
75.75.-c
Opis:: In this work we have studied the structural and magnetic properties of "as-prepared" multiwalled carbon nanotubes, synthesized by the chemical vapor deposition method, and chemically modified multiwalled carbon nanotubes. Transmission electron microscopy was used to show multiwalled carbon nanotubes structure. The results of systematic magnetic property measurements on multiwalled carbon nanotubes are presented. The static and dynamic magnetic responses, such as the temperature dependence of the linear AC susceptibility and DC magnetization up to 9 T were studied. We have observed significant changes in magnetic AC susceptibility and magnetization for "as-prepared" and chemically modified multiwalled carbon nanotubes samples.
Źródło:: Acta Physica Polonica A; 2011, 119, 5; 597-599
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 22.

Tytuł:: Magnetoimpedance Effects in Electrodeposited NiFe Nanowire Array
Autorzy:: Aydogmus, E.
Kaya, H.
Atalay, F.
Atalay, S.
Avcu, D.
Powiązania:: https://bibliotekanauki.pl/articles/1207745.pdf
Data publikacji:: 2014-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.07.Gf
81.15.Pq
75.75.-c
Opis:: In this work, NiFe nanowires were grown in highly ordered porous anodic alumina oxide templates by dc electrodeposition at a pH value of 2.6. Scanning electron microscopy showed that wires have diameters of about 250-310 nm and length 25-30 μm. The energy dispersive X-ray analysis showed that the composition of the nanowires is $Ni_{65}Fe_{35}$. Electrical contacts were made on both sides of the nanowire array and their magnetoimpedance properties were investigated. All the magnetoimpedance curves showed single peak behavior due to the high shape anisotropy. The maximum magnetoimpedance change at the 79 MHz driving current frequency was ≈ 1.45%.
Źródło:: Acta Physica Polonica A; 2014, 125, 2; 227-229
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 23.

Tytuł:: Magnetoresistance of Electrodeposited Co/Cu Multilayer Nanowires
Autorzy:: Avcu, D.
Atalay, F.
Atalay, S.
Kaya, H.
Aydogmus, E.
Powiązania:: https://bibliotekanauki.pl/articles/1401297.pdf
Data publikacji:: 2015-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.07.Gf
81.15.Pq
75.75.-c
Opis:: Co/Cu multilayer nanowires were electrodeposited potentiostatically on highly ordered porous anodic alumina oxide templates. Scanning electron microscopy (SEM) showed that wires have diameters of about 250-300 nm and length of 40-50 μm. Co/Cu multilayer nanowire arrays embedded in anodic alumina oxide were mechanically polished with diamond in a suspension of oil until the wires appeared. Then the top and bottom surfaces of the material were coated with a layer of Au with a thickness of 100 nm for electrical contacts. Magnetic field was applied by an electromagnet and resistance was measured by four point technique.
Źródło:: Acta Physica Polonica A; 2015, 127, 4; 1115-1117
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 24.

Tytuł:: Magnetism of Nanoparticle $La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3$ under Applied Hydrostatic Pressure
Autorzy:: Kusigerski, V.
Perovic, M.
Mrakovic, A.
Blanusa, J.
Mihalik, M.
Zentkova, M.
Spasojevic, V.
Powiązania:: https://bibliotekanauki.pl/articles/1534028.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Tt
75.75.-c
81.07.Bc
Opis:: Nanoparticle $La_{0.7}Ca_{0.3}Mn_{0.7}Fe_{0.3}O_3$ with the average particle size of 10 nm was mechanochemically synthesized in the single-step procedure. Temperature and field dependences of magnetization were recorded under both ambient and applied hydrostatic pressure up to 0.47 GPa. At ambient pressure, two magnetic transition points were observed: one of the spin-glass like type at the temperature $T_{f}$ ≈ 34 K, and ferro-to-paramagnet transition at $T_{C}$ ≈ 51 K. Under the applied pressure magnetic parameters gradually changed: (i) both $T_{C}$ and $T_{f}$ were lowered with the increase in pressure; (ii) both high field magnetization $M_{5T}$ and remanent magnetization $M_{Rem}$ decreased with pressure; (iii) coercivity $H_{C}$ increased with pressure. The obtained results show that magnetism of a nanoparticle system with high degree of intrinsic disorder diminishes with the applied pressure that is in compliance with the effect of the increased cationic disorder ("internal pressure") in bulk manganites.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 811-812
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 25.

Tytuł:: Fabrication and Study of the Magnetic Properties of $(Fe_{30}Co_{70})_{100-x}Zn_{x}$ Nanowire Arrays
Autorzy:: Sedghi, A.
Zolfi, F.
Vali Aghaie, S.
Powiązania:: https://bibliotekanauki.pl/articles/1400557.pdf
Data publikacji:: 2015-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.07.Gf
81.15.Pq
75.75.-c
Opis:: $(Fe_{30}Co_{70})_{100-x}Zn_{x}$ (0 ≤ x ≤ 10) nanowires with diameters of ≈ 37 nm have been fabricated by AC electrodeposition into pores of anodized aluminum oxide (AAO) templates. The $Fe_{30}Co_{70}$ and Zn contents of the nanowires have been adjusted by varying the ratio of $Fe_{30}Co_{70}$ and Zn ion concentrations in the electrolyte. The effect of the Zn content and annealing on the magnetic properties (e.g., coercivity and squareness) of nanowires arrays have been investigated using X-ray diffraction, scanning electron microscopy, and alternating gradient force magnetometer. X-ray diffraction patterns reveal that an increase in the concentration of Zn ions of the electrolyte results in significant reduction in coercivity and squareness. It was found that the magnetic properties of nanowires can be significantly improved by appropriate annealing process. The highest values for coercivity (2670 Oe) and squareness (0.99) have been obtained for nanowires electrodeposited using 95/5 and 98/2 $Fe_{30}Co_{70}:Zn$ concentrations at annealing temperatures of 575°C and 550°C, respectively.
Źródło:: Acta Physica Polonica A; 2015, 127, 6; 1706-1711
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 26.

Tytuł:: Magnetic Properties of $V_{2}O_{3}$ Nanooxide Prepared Mechanochemically With and Without Salt Matrix
Autorzy:: Dvurečenskij, A.
Billik, P.
Cigáň, A.
Bystrický, R.
Maňka, J.
Škrátek, M.
Majerová, M.
Powiązania:: https://bibliotekanauki.pl/articles/1372489.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 85.25.Dq
75.75.-c
61.46.+w
Opis:: We present a new technological route of synthesis of $V_{2}O_{3}$ nanocrystals based on mechanochemical reduction of $V_{2}O_{5}$ with $Na_{2}SO_{3}$ as a reductant, followed by low temperature vacuum annealing. The structural and magnetic properties of the $V_{2}O_{3}$ nanocrystals were studied.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 398-399
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 27.

Tytuł:: The Novel Multichannel Single Photon Correlations Technique Applied for the Spin Dynamics Study of a Few Mn^{2+} Ions in a CdTe/ZnTe Quantum Dot
Autorzy:: Malinowski, F.
Koperski, M.
Goryca, M.
Smoleński, T.
Golnik, A.
Kossacki, P.
Wojnar, P.
Powiązania:: https://bibliotekanauki.pl/articles/1399084.pdf
Data publikacji:: 2013-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.67.Hc
72.21.La
75.75.-c
Opis:: In this work we demonstrate a novel experimental approach to the study of single photon correlations. The introduction of the multichannel detection setup enables the simultaneous measurement of a large number of correlation functions for photons emitted from different energetic ranges. The advantages of this new approach were exploited in a detailed study of the biexciton-exciton recombination cascade in CdTe/ZnTe quantum dots doped with a few $Mn^{2+}$ ions. The information about the dynamics of the magnetic system in the quantum dot during the lifetime of the exciton was obtained from the analysis of the correlation functions.
Źródło:: Acta Physica Polonica A; 2013, 124, 5; 791-794
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 28.

Tytuł:: Frustration Measure for Molecular Magnets with Single-Ion Anisotropy
Autorzy:: Kozłowski, P.
Powiązania:: https://bibliotekanauki.pl/articles/1030687.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.45.+j
75.50.Xx
75.75.-c
03.67.Mn
Opis:: The universal frustration measure and its extension to anisotropic systems is calculated for a family of spin Hamiltonians modeling a hypothetical ring-shaped chromium-based molecular magnets. The proposed extension takes into account the impact of single-ion anisotropy on the magnetic centers and behaves more consistently with respect to the isotropic counterpart. The influence of anisotropy on both measures is assessed, which leads to a conclusion that frustration decreases with increasing absolute value of single ion anisotropy.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 423-425
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 29.

Tytuł:: Thickness Dependence of Mössbauer Parameters for Fe₇₈Si₉B₁₃ Metallic Glass Ribbons
Autorzy:: Amini, N.
Miglierini, M.
Hasiak, M.
Dekan, J.
Habibi, S.
Powiązania:: https://bibliotekanauki.pl/articles/1032172.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Kj
75.60.Ej
75.75.-c
76.80.+y
Opis:: Changes in magnetic microstructure of Fe₇₈Si₉B₁₃ ribbons were investigated by the Mössbauer spectrometry as a function of their thickness. The latter decreases inversely with the quenching wheel velocity. Amorphicity of the samples was checked by X-ray diffraction and the Mössbauer spectrometry. Average values of hyperfine magnetic fields do not appreciably differ with the production velocity. On the other hand, notable deviations are observed in the position of a net magnetic moment. After annealing with moderate temperature, the magnetic anisotropy improves as indicated by an increase of the average value of hyperfine magnetic field. However, magnetic moments turn out of the ribbon plane and this process continues towards higher production velocity, i.e., smaller thickness of the ribbons. No appreciable deviations in the investigated Mössbauer parameters were revealed after annealing during different time intervals.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 666-668
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 30.

Tytuł:: Magnetic Properties of Epitaxial Fe/(Ga,Mn)As Hybrids
Autorzy:: Kalbarczyk, K.
Dziatkowski, K.
Szczytko, J.
Gosk, J.
Tokarczyk, M.
Kowalski, G.
Twardowski, A.
Bednarski, W.
Ostrowski, A.
Waplak, S.
Martinek, J.
Liu, X.
Furdyna, J.
Powiązania:: https://bibliotekanauki.pl/articles/1399140.pdf
Data publikacji:: 2013-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.30.Gw
75.50.Pp
75.50.Bb
Opis:: Thin-film structures composed of two kinds of ferromagnetic material - metallic Fe and semiconducting (Ga,Mn)As - were investigated by means of SQUID magnetometry and ferromagnetic resonance spectroscopy. Dependence of remnant magnetic moment on temperature showed unexpected anisotropic features when recorded along two orthogonal in-plane directions. For one of these orientations, the change in sign of the slope of m(T) curve at the Curie point of (Ga,Mn)As was observed, while for the other, an analogous m(T) curve retained monotonic character. Based on the comparison with ferromagnetic resonance data, the apparent non-monotonicity was attributed to the temperature-induced change of balance between the external magnetic field and uniaxial magnetic anisotropy in the plane of Fe layer.
Źródło:: Acta Physica Polonica A; 2013, 124, 5; 873-876
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 31.

Tytuł:: Mössbauer Studies of Core-Shell Nanoparticles.
Autorzy:: Kalska-Szostko, B.
Cydzik, M.
Satuła, D.
Giersig, M.
Powiązania:: https://bibliotekanauki.pl/articles/1506313.pdf
Data publikacji:: 2011-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 82.80.Ej
81.07.-b
75.75.-c
81.16.-c
Opis:: The ferrite magnetic nanoparticles with core-shell structures were obtained in two step preparation process. The Mössbauer spectra obtained for particles of pure maghemite or magnetite and two layered core-shell one the magnetite on maghemite and maghemite on magnetite are very different from each other. The presented results show that interparticle and intraparticle interaction plays important role in overall magnetic properties as well.
Źródło:: Acta Physica Polonica A; 2011, 119, 1; 15-17
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 32.

Tytuł:: Effects of Intrinsic Forces in Toroidal Cores Wound of Soft-Magnetic Ribbons
Autorzy:: Butvinová, B.
Butvin, P.
Švec, P.
Chromčíková, M.
Vlasák, G.
Powiązania:: https://bibliotekanauki.pl/articles/1534033.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.20.En
75.60.Ej
75.75.-c
81.40.-z
Opis:: Magnetic anisotropy as shown by hysteresis loops of tape-wound toroidal cores has been inspected as to the specific response of the anisotropy to core-internal forces during and after annealing. The loops of toroids are compared to that of strip samples annealed together in various ambience. The core-internal forces were manipulated by means of different core construction, too. The results show that it is the heterogeneity, which produces the most effective forces. Different annealing-induced ribbon shrinkage makes the cores effectively heterogeneous and governs their magnetic response, whereas inherent ribbon heterogeneity affects the core properties, too, and is essential for homogeneous cores.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 815-817
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 33.

Tytuł:: Magnetic Properties of the Nanocrystalline $DyMnO_{3}$ Compound
Autorzy:: Dyakonov, V.
Szytuła, A.
Baran, S.
Kravchenko, Z.
Zubov, E.
Iessenchuk, O.
Bazela, W.
Dul, M.
Zarzycki, A.
Szymczak, H.
Powiązania:: https://bibliotekanauki.pl/articles/1538453.pdf
Data publikacji:: 2010-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.05.cp
75.47.Lx
75.50.Ee
75.75.-c
Opis:: We report on the X-ray powder diffraction and magnetic measurements of the polycrystalline and the two nanocrystalline samples of $DyMnO_{3}$ compound synthesized at temperatures of 800 and 850°C. All samples at room temperature crystallize in the orthorhombic crystal structure (space group Pnma). The crystal structure parameters determined change only slightly with preparation methods but the average grains size of the nanoparticles determined from X-ray data increases significantly with increasing annealing temperature. Temperature dependence of the magnetic susceptibility indicates the antiferromagnetic order in Dy sublattice at low temperatures.
Źródło:: Acta Physica Polonica A; 2010, 117, 4; 607-610
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 34.

Tytuł:: Characterization of Carbon Nanotubes
Autorzy:: Jeníková, M.
Zakuťanská, K.
Kováč, J.
Girman, V.
Kopčanský, P.
Tomašovičová, N.
Powiązania:: https://bibliotekanauki.pl/articles/1032760.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.48.De
74.25.nd
68.37.Lp
75.75.-c
Opis:: The aim of the presented work was to characterize single-walled carbon nanotubes as well as multi-walled carbon nanotubes by transmission electron microscopy, the Raman spectroscopy and magnetization measurements to obtain information about their size, structure, and magnetic properties. We show that having different carbon nanotubes one can easily distinguish the single-wall or multi-wall carbon nanotubes and determine their quality. The obtained results show that carbon nanotubes can be diamagnetic or ferromagnetic depending on their structural parameters.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 952-954
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 35.

Tytuł:: Transformation of Hyperfine Interactions in Co-Substituted Nanoperm-Type Alloys during Annealing
Autorzy:: Hatala, T.
Miglierini, M.
Powiązania:: https://bibliotekanauki.pl/articles/1507056.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.80.+y
71.55.Jv
42.25.Fx
75.75.-c
Opis:: Structure and magnetic order of rapidly quenched $(Fe_{1-x}Co_{x})_{79}Mo_8Cu_1B_{12}$ alloys is investigated by $\text{}^{57}Fe$ Mössbauer spectrometry in transmission geometry and by conversion electron Mössbauer spectrometry. The effect of heat treatment upon hyperfine interactions was studied as a function of Co contents (x = 0, 0.5). Magnetic dipole interactions developed in both alloys when sufficient number of ferromagnetic nanograins is created after heat treatment. The kinetics of crystallization was derived from in situ diffraction of synchrotron radiation. The progress of crystallization is different at both sides of the ribbon-shaped samples.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 764-765
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 36.

Tytuł:: Size Dependence of Magnetic and Optical Properties of $Co_3O_4$ Nanoparticles
Autorzy:: Sarfraz, A.
Hasanain, S.
Powiązania:: https://bibliotekanauki.pl/articles/1206616.pdf
Data publikacji:: 2014-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 81.05.Gc
61.05.cp
75.75.-c
78.66.-w
Opis:: The effect of particle size on the magnetic and optical properties of cobalt oxide $Co_3O_4$ has been investigated. Single phase $Co_3O_4$ nanoparticles were synthesized by co-precipitation route and their structure was confirmed through X-ray diffraction analysis. The average crystallite sizes of the nanoparticles as determined from the X-ray diffraction were found to lie in the range of 13 to 59 nm. At room temperature these particles show paramagnetic response and the DC magnetic moment of the samples showed an increasing trend with increasing particle size. Both the antiferromagnetic Néel temperature $T_{N}$ and the low temperature moment depict finite size effects in the AC susceptibility measurements. The optical absorption studies show that there are two direct band gaps in $Co_3O_4$, the main energy band gap and a sub-band located inside the main energy gap. The values of these energy band gaps for the 45 nm particles were determined to be 3.15 and 1.76 eV, respectively. The direct band gap in these particles clearly shows a blue shift with decreasing size attributable to the quantum confinement effect.
Źródło:: Acta Physica Polonica A; 2014, 125, 1; 139-144
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 37.

Tytuł:: Temperature behaviour of hyperfine magnetic fields in a Fe-Co-Si-B-Mo-P metallic glass followed with ⁵⁷Fe Mössbauer spectrometry
Autorzy:: Cesnek, M.
Miglierini, M.
Kmječ, T.
Kohout, T.
Amini, N.
Janičkovič, D.
Matúš, P.
Powiązania:: https://bibliotekanauki.pl/articles/1053048.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Kj
75.60.Ej
75.75.-c
76.80.+y
Opis:: Amorphous glass with nominal chemical composition Fe₅₁Co₁₂Si₁₆B₈Mo₅P₈ was studied by combination of the Mössbauer spectroscopy and magnetic measurements in order to characterize magnetic and structural features. Temperature evolution of the Mössbauer spectra revealed presence of broad distribution of hyperfine magnetic field at lower temperatures which vanishes with increase of temperature. The Curie temperature estimated from the Mössbauer spectroscopy experiments is T_{C} ≈ 392 K. This value is in a good agreement with that obtained by magnetic measurements (T_{C}=397 K). The Mössbauer spectroscopy spectra of the sample annealed at 823 K revealed a presence of crystalline components. This temperature is notably lower than the expected temperature of the onset of crystallization observed by differential scanning calorimetry ( ≈ 835 K).
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 744-746
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 38.

Tytuł:: Dependence of Ultrasonic and Magnetic Hyperthermia on the Concentration of Magnetic Nanoparticles
Autorzy:: Kaczmarek, K.
Hornowski, T.
Bielas, R.
Żak, D.
Timko, M.
Józefczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/1030383.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
43.35.Cg
43.35.Wa
87.85.-d
Opis:: Hyperthermia treatment is the heating of tumor tissue up to temperatures between 41°C and 45°C, which trigger several physiological reactions in the body. Hyperthermia within tissue can be applied through various mechanisms. One of them is magnetic hyperthermia which uses superparamagnetic iron oxide nanoparticles (SPIONs) heated by an externally applied magnetic field. SPIONs can also be used as sonosensitizers in ultrasound hyperthermia increasing acoustic wave attenuation. The impact of SPION concentration on thermal effect during ultrasonic and magnetic hyperthermia was investigated in agar-gel phantom with added magnetite nanoparticles. The presence of nanoparticles in the tissue-mimicking phantom increases the thermal losses of ultrasound energy and temperature of the phantom.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 716-718
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 39.

Tytuł:: Exciton Binding Energy and Oscillator Strength in a Shallow Quantum Well in an External Magnetic Field
Autorzy:: Zięba, P.
Piętka, B.
Łusakowski, J.
Tralle, I.
Powiązania:: https://bibliotekanauki.pl/articles/1402589.pdf
Data publikacji:: 2015-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.35.Ji
75.75.-c
73.21.Fg
62.20.-x
Opis:: We discuss the influence of an external magnetic field on the exciton energy and the exciton oscillator strength in the shallow quantum wells. We include into consideration the Coulomb attraction between electron and hole, which is rarely taken into account. We self-consistently solve the Schrödinger equation to compare the obtained results with the experimental values.
Źródło:: Acta Physica Polonica A; 2015, 128, 2; 237-239
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 40.

Tytuł:: Type-II InAs/GaAsSb/GaAs Quantum Dots as Artificial Quantum Dot Molecules
Autorzy:: Klenovský, P.
Křápek, V.
Humlíček, J.
Powiązania:: https://bibliotekanauki.pl/articles/1398560.pdf
Data publikacji:: 2016-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.21.La
75.75.-c
85.35.Be
68.65.Hb
Opis:: We have studied theoretically the type-II GaAsSb capped InAs quantum dots for two structures differing in the composition of the capping layer, being either (i) constant or (ii) with Sb accumulation above the apex of the dot. We have found that the hole states are segmented and resemble the states in the quantum dot molecules. The two-hole states form singlet and triplet with the splitting energy of 4 μeV/325 μeV for the case (i)/(ii). We have also tested the possibility to tune the splitting by vertically applied magnetic field. Because the predicted tunability range was limited, we propose an approach for its enhancement.
Źródło:: Acta Physica Polonica A; 2016, 129, 1a; A-62-A-65
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 41.

Tytuł:: Temperature of a Single Mn Atom in a CdTe Quantum Dot
Autorzy:: Papierska, J.
Goryca, M.
Wojnar, P.
Kossacki, P.
Powiązania:: https://bibliotekanauki.pl/articles/1791341.pdf
Data publikacji:: 2009-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.67.Hc
71.70.Gm
78.55.Et
75.75.-c
Opis:: In this work we present a study of the temperature of the single magnetic atom embedded in a semiconductor quantum dot versus excitation power and magnetic field. This temperature is defined by the thermal distribution of spin states of single Mn ion, and results from its interaction with the neighborhood. This temperature was found to be much higher than the temperature of the thermal bath. Its dependence on the excitation power and magnetic field is discussed.
Źródło:: Acta Physica Polonica A; 2009, 116, 5; 899-900
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 42.

Tytuł:: Mössbauer and SQUID Characterization of Iron in Human Tissue: Case of Globus Pallidus
Autorzy:: Miglierini, M.
Boča, R.
Kopáni, M.
Lančok, A.
Powiązania:: https://bibliotekanauki.pl/articles/1382185.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.80.+y
31.30.Gs
75.75.-c
87.85.jc
Opis:: Lyophilized samples of human brain tissue from the region of Globus Pallidus were investigated in powder form by $\text{}^{57}Fe$ Mössbauer spectroscopy and SQUID magnetometry. The obtained hyperfine parameters including isomer shift and quadrupole splitting exhibit a ferritin-like behaviour with high-spin Fe(III) sites. Three types of features were derived from temperature development of magnetic susceptibility: dominating diamagnetism, dominating paramagnetism, and intermediate states. The magnetic characteristics of the samples do not correlate with age of the donors.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 240-241
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 43.

Tytuł:: Magnetization Dynamics of a (Cd,Mn)Te Quantum Well in Pulsed Magnetic Field
Autorzy:: Kobak, J.
Goryca, M.
Kossacki, P.
Golnik, A.
Karczewski, G.
Wojtowicz, T.
Gaj, J.
Powiązania:: https://bibliotekanauki.pl/articles/1791344.pdf
Data publikacji:: 2009-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.67.Hc
71.70.Gm
78.55.Et
75.75.-c
Opis:: In this paper we present studies of magnetization relaxation in a (Cd,Mn)Te quantum well containing 3.2% of Mn, after a pulse of magnetic field. The relaxation was found to be very fast, with dominant component faster than 10 ns. Upon application of static magnetic field the relaxation does not slow down, in contrast with the behavior of very diluted quantum wells or bulk material.
Źródło:: Acta Physica Polonica A; 2009, 116, 5; 907-908
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 44.

Tytuł:: Magnetoluminescence of a CdTe Quantum Dot with a Single Manganese Ion in Voigt Configuration
Autorzy:: Koperski, M.
Goryca, M.
Kazimierczuk, T.
Kossacki, P.
Wojnar, P.
Gaj, J. A.
Powiązania:: https://bibliotekanauki.pl/articles/2047960.pdf
Data publikacji:: 2011-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.21.La
75.75.-c
78.55.Et
78.67.Hc
Opis:: We present a study of the neutral exciton and negative trion recombination spectra of an individual CdTe quantum dot with a single manganese ion, in magnetic field measured in the Voigt configuration. We describe experimental results and compare with a theoretical model. The quantitative agreement between the model and the experiment allows us to determine separately the electron g-factor.
Źródło:: Acta Physica Polonica A; 2011, 119, 5; 618-620
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 45.

Tytuł:: Template Assisted Deposition of Ferromagnetic Nanostructures: from Antidot Thin Films to Multisegmented Nanowires
Autorzy:: Prida, V.M.
Salaheldeen, M.
Pfitzer, G.
Hidalgo, A.
Vega, V.
González, S.
Teixeira, J.
Fernández, A.
Hernando, B.
Powiązania:: https://bibliotekanauki.pl/articles/1032144.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Gw
75.70.Kw
75.75.-c
75.70.-i
75.70.Rf
Opis:: The growth of nanostructured materials by means of different deposition methods employing nanoporous anodic aluminum oxide membranes as patterned templates has been widely used during last years due to the outstanding features displayed by these nanoporous templates. Here we report on the synthesis, morphology and magnetic properties exhibited by novel magnetic 1D and 2D nanostructured materials having nanowire or antidot thin films geometry, respectively, together to that of geometrically diameter modulated ferromagnetic nanowires. Their magnetic properties will be analyzed and discussed based on the different anisotropic behavior derived from their morphological and microstructural features.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 822-827
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 46.

Tytuł:: Preparation and Magnetic Characteristics of $Co_{1-δ}Zn_{δ}Fe_2O_4$ Ferrite Nanopowders
Autorzy:: Kubisztal, M.
Herok, I.
Karolus, M.
Prusik, K.
Haneczok, G.
Powiązania:: https://bibliotekanauki.pl/articles/1398315.pdf
Data publikacji:: 2017-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.47.Lx
75.50.Gg
75.50.Tt
75.75.-c
75.75.Cd
Opis:: In the present paper the $Co_{1-δ}Zn_{δ}Fe_2O_4$ (0 ≤ δ ≤ 1) ferrite nanopowders with a spinel type structure were synthesized using a chemical co-precipitation technique with constant flow rate $ν _{FR}$=120 cm³/min at three different reaction temperatures i.e. $T_r$ =50°C, 70°C and 90°C. Magnetic and structural characteristics of the obtained materials were investigated by means of X-ray diffraction method, transmission electron microscopy and vibrating sample magnetometer. In the course of studies hysteresis loops M(μ₀H) and the relations of magnetization $M_{7T}$ (determined at $\text{}_{μ0}H $=7 T), squareness ratio S and the Néel temperature $T_{N}$ versus Zn content were determined and discussed in detail. It was shown that for δ<0.6 the increase in reaction temperature $T_r$ results in a significant increase of the measured magnetic characteristics. In particular, in the case of $Co_{0.8}Zn_{0.2}Fe_2O_4$ ferrite nanopowder magnetization $M_{7T}$ reaches maximal value of about 80 emu/g.
Źródło:: Acta Physica Polonica A; 2017, 131, 5; 1236-1239
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 47.

Tytuł:: Fine Smoothing of Conductive Substrate for Permalloy Layer Electroplating
Autorzy:: Butta, M.
Janosek, M.
Pilarcikova, I.
Kraus, L.
Powiązania:: https://bibliotekanauki.pl/articles/1201077.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.30.-m
75.50.-y
07.55.-w
75.70.-i
Opis:: In this paper we study the influence of the roughness of the copper substrate on the magnetic properties of the FeNi film we electroplate onto it. The roughness and the thickness of the copper substrate are reduced by electropolishing in orthophosphoric acid: we show how to select the working point, which gives the highest smoothness, avoiding defects due to gas evolution. Finally we show how a smoother substrate contributes to reducing the coercivity of the magnetic film grown on it.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 150-151
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 48.

Tytuł:: Magnetic Hyperfine Fields of Nanoperm Alloys
Autorzy:: Miglierini, M.
Kohout, J.
Lančok, A.
Šafářová, K.
Powiązania:: https://bibliotekanauki.pl/articles/1428957.pdf
Data publikacji:: 2012-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Tt
75.75.-c
76.80.+y
76.60.-k
68.37.Rt
Opis:: Magnetic hyperfine fields of $Fe_{90}Zr_7B_3$ Nanoperm nanocrystalline alloy are characterized by $\text{}^{57}Fe$ Mössbauer spectrometry and $P^{57}Fe$ NMR as well as by magnetic force microscopy. $\text{}^{57}Fe$ NMR enables to distinguish a broad signal of iron atoms located in a residual amorphous matrix from a narrow one which belongs to Fe in nanograins. The former coincides with the distribution of hyperfine fields obtained from $\text{}^{57}Fe$ Mössbauer spectroscopy. In addition, it is possible to make a distinction between NMR signals of the Fe nanograins located in magnetic domains from that of the nanograins positioned in domain walls. This is confirmed by magnetic force microscopy where appearance of maze-domains is observed.
Źródło:: Acta Physica Polonica A; 2012, 121, 5-6; 1263-1265
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:: Effects of Core Dimensions and Manufacturing Procedure on Fluxgate Noise
Autorzy:: Janošek, M.
Vyhnánek, J.
Zikmund, A.
Butvin, P.
Butvinová, B.
Powiązania:: https://bibliotekanauki.pl/articles/1367343.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
75.30.-m
75.50.-y
07.55.-w
75.70.-i
Opis:: The effect of demagnetizing factor and manufacturing procedure on noise of the fluxgate probes, manufactured from metallic glasses, is presented. The fluxgate probes were either tape-wound, or flat, wet-etched ringcore and race-track geometries. When combining low demagnetizing factor and high enough cross-section of the probe, a minimum in the noise dependence can be found. For 50 mm ringcores, in such minimum the noise value as low as $7 pT_{RMS}$ in 0.1-10 Hz frequency band was achieved, which is very low for an as-cast tape, and has not been reported before.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 104-105
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:: Size dependent heating efficiency of multicore iron oxide particles in low-power alternating magnetic fields
Autorzy:: Smolkova, I.
Kazantseva, N.
Vitkova, L.
Babayan, V.
Vilcakova, J.
Smolka, P.
Powiązania:: https://bibliotekanauki.pl/articles/1054706.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.47.Lx
75.50.Mm
75.60.Jk
75.75.-c
75.78.-n
Opis:: Aggregates of superparamagnetic nanoparticles, so called multicore particles get much attention due to collective magnetic behaviour. Despite the fact that saturation magnetization and coercivity of multicore particles are lower than for single particles of comparable size, they can generate large amount of heat in alternating magnetic field. This makes them promising for magnetic hyperthermia. However, correlation between internal magnetic structure of multicore particles and their heating ability in alternating magnetic fields are not clear yet. Detailed experimental investigations are required to determine the optimal sizes of multicore particles and the alternating magnetic field parameters to obtain maximal heat. In this study, we demonstrated how hydrodynamic size of multicore particles influences alternating magnetic field energy absorption. Dense aggregates composed of bare magnetic iron oxide nanoparticles of 13 nm were obtained by coprecipitation. Further peptization allowed to gain aqueous dispersions of multicore particles with various hydrodynamic size, varing from 85 to 170 nm, due to electrostatic stabilization. Multicore particles dispersions have saturation magnetization of 40 A m²/kg_{Fe₃O₄} and coercivity of 79.6 A/m regardless of their size. Dispersion of 85 nm multicore particles is stable and provides specific loss power of 42 W/g_{Fe}. Further increase of hydrodynamic size leads to low stability and loss of the ability to generate heat in alternating magnetic field.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 663-665
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 51.

Tytuł:: Effect of Surfactant on Magnetic and Optical Properties of $α-Fe_2O_3$ Nanoparticles
Autorzy:: Mirza, I.
Sarfraz, A.
Hasanain, S.
Powiązania:: https://bibliotekanauki.pl/articles/1377739.pdf
Data publikacji:: 2014-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.66.Qn
75.47.Lx
78.67.Bf
75.75.-c
78.67.-n
Opis:: Hematite $(α-Fe_{2}O_{3})$ nanoparticles and hematite nanoparticles coated with polyvinylpyrrolidone (PVP) are synthesized chemically by co-precipitation. Prolysis and microemulsion methods respectively. An average size of nanoparticles (both coated and uncoated) was found by the broadening of the X-ray diffraction peaks using Scherrer's formula. It was found that coating reduced particle sizes. The attachment of the polymer on the surface of particles was confirmed by the Fourier transform infrared spectroscopy and thermogravimetric analysis. Optical ultraviolet/visible reflectance test also indicated the presence of PVP in coated nanohematites. In magnetic studies, it was observed that coating does not change main magnetic character of the $α-Fe_{2}O_{3}$ nanoparticles however it reduces DC magnetization (as a function of applied field and temperature) to a considerable amount. Moreover it was observed that after coating Morin transition temperature $T_{M}$ and its width $ΔT_{M}$ shifts to lower values, which is another indication of size reduction.
Źródło:: Acta Physica Polonica A; 2014, 126, 6; 1280-1287
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 52.

Tytuł:: Structural Design and Characterization of $BaMg_{x}Co_{2-x}Fe_{16}O_{27}$ Hexaferrites Based on ab initio Computations
Autorzy:: Bakhtiari, M.
Nabiyouni, G.
Besharati-Seidani, A.
Powiązania:: https://bibliotekanauki.pl/articles/1378257.pdf
Data publikacji:: 2014-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Gg
71.20.-b
75.75.-c
71.15.Mb
71.15.Dx
Opis:: Structural design of barium hexaferrites $BaMg_xCo_{2-x}Fe_{16}O_{27}$ (x=0.0, 1, 2) has been studied, and the magnetic and electronic structure of that has then been investigated using first principle total energy calculation. All calculations are based on the density functional theory. In order to improve the description of strongly correlated 3d electrons of iron, the general gradient approximation plus Hubbard U (GGA+U) method is used. We found that in the lowest energy configuration Mg and Co ions preferentially occupy the 6g sites. With the increase of Mg content x, the energy gap of $BaMg_xCo_{2-x}Fe_{16}O_{27}$ increases but the lattice constant of unit cell decreases. The magnetic moment of the unit cell for Mg content x=0, 1, and 2 are calculated to be 52, 49 and 46 $μ_{B}$/cell, respectively, in agreement with previous experimental results. The substitutions of Mg and Co at the $BaFe_2^{2+}Fe_{16}^{3+}O_{27}$ decrease electrical conductivity and transit it from a half-metal to semiconductor material. Based on our calculations on electronic band structure, the $BaFe_2Fe_{16}O_{27}$ (BFFO) is a weak half-metal, but $BaMg_2Fe_{16}O_{27}$ (BMFO), $BaMgCoFe_{16}O_{27}$ (BMCFO) and $BaCo_2Fe_{16}O_{27}$ (BCFO) are semiconductors. The electrical resistivity increases by increasing Mg and Co contents due to increase in porosity which prevents the hopping of charge carriers.
Źródło:: Acta Physica Polonica A; 2014, 126, 6; 1288-1292
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 53.

Tytuł:: Mössbauer Spectrometry Study of Biological Tissues
Autorzy:: Bonková, I.
Miglierini, M.
Bujdoš, M.
Kopáni, M.
Powiązania:: https://bibliotekanauki.pl/articles/1032139.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 33.45.+x
87.64.kx
31.30.Gs
87.15.B-
75.75.-c
Opis:: Magnetic microstructure of iron contained in selected biological tissues is characterized and mutually compared. We have studied three types of biological samples prepared from human brain, human and horse spleen. Original samples were lyophilized (dried in a vacuum) thus providing powder forms. As a principal method of study, ⁵⁷Fe Mössbauer spectrometry in transmission mode was used. The Mössbauer spectrometry experiments were performed at room ( ≈300 K) and at liquid helium (4.2 K) temperature. At room temperature Mössbauer spectra show doublet-like features. Such behaviour indicates possible presence of nanoparticles with fluctuating magnetic moments that acquire arbitrary positions. On the other hand, low temperature Mössbauer spectrometry measurements demonstrate significant contribution of sextets that confirmed occurrence of blocked magnetic moments of iron-containing particles. Different relative contributions of magnetic components in the low temperature spectra for the three inspected biological tissues suggest differences in the blocking temperatures of the magnetic nanoparticles present in them.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 1081-1083
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 54.

Tytuł:: Structural and Magnetic Properties of Nano-Sized NiZn Ferrites
Autorzy:: Ušák, E.
Šoka, M.
Ušáková, M.
Dobročka, E.
Powiązania:: https://bibliotekanauki.pl/articles/1366899.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Gg
75.50.Tt
61.46.Df
61.05.C-
75.30.Cr
75.75.-c
Opis:: Structural and magnetic properties (such as e.g. size of crystallites, lattice parameter, magnetic susceptibility, Curie temperature, etc.) of nano-sized $Ni_{0.33}Zn_{0.67}Fe_{2}O_{4}$ ferrites have been studied. The obtained results demonstrated that the sintering temperature is an efficient and simple tool for controlling the size of crystallite particles, thus affecting the resulting magnetic properties. Straightforward relationship between the sintering temperature and the size of crystallites was found, meanwhile no other crystalline phases than the spinel one were detected by two independent analytic methods.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 68-69
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 55.

Tytuł:: Magnetostructural Correlations of Nano-Sized Manganites Prepared by Different Ways
Autorzy:: Vavra, M.
Mihalik, Marián
Mihalik, Matúš
Zentková, M.
Lazurová, J.
Matik, M.
Briančin, J.
Arnold, Z.
Maryško, M.
Powiązania:: https://bibliotekanauki.pl/articles/1371215.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.-y
75.47.Lx
75.30.-m
75.75.-c
68.37.Hk
61.05.cp
Opis:: We present the preparation and magnetostructural correlations of binary $NdMnO_{3}$ oxide prepared by four different procedures. Nano-size particle were prepared by simple precipitation of hydroxides (PH), nitrate-glycine synthesis (NG) and self-combustion high-temperature synthesis (SHS), while sol-gel method (SG) produced particles with size of about 2 μm. The as prepared PH and SG particles exhibit amorphous structure, the orthorhombic crystal structure was observed for NG and SHS particles. As prepared PH, NG and SHS are magnetically ordered, annealing leads to magnetic ordering of SG particles.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 304-305
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 56.

Tytuł:: Exact Diagonalization Study of an Extended Hubbard Model for a Cubic Cluster at Quarter Filling
Autorzy:: Szałowski, K.
Balcerzak, T.
Jaščur, M.
Bobák, A.
Žukovič, M.
Powiązania:: https://bibliotekanauki.pl/articles/1032794.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Cx
75.75.-c
75.10.Lp
71.27.+a
65.80.-g
05.70.Ce
Opis:: In the paper the thermodynamics of a cubic cluster with 8 sites at quarter filling is characterized by means of exact diagonalization technique. Particular emphasis is put on the behaviour of such response functions as specific heat and magnetic susceptibility. The system is modelled with extended Hubbard model which includes electron hopping between both first and second nearest neighbours as well as Coulombic interactions, both on-site and between nearest-neighbour sites. The importance of hopping between second nearest neighbours and Coulombic interactions between nearest neighbours for the temperature dependences of thermodynamic response functions is analysed. In particular, the predictions of the Schottky model are compared with the calculations based on the full energy spectrum.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 1012-1014
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 57.

Tytuł:: Magnetic Polymer Nanocomposite for Medical Application
Autorzy:: Świętek, M.
Tokarz, W.
Tarasiuk, J.
Wroński, S.
Błażewicz, M.
Powiązania:: https://bibliotekanauki.pl/articles/1197651.pdf
Data publikacji:: 2014-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 82.35.Np
87.85.-d
87.85.Rs
75.75.-c
87.85.J-
87.85.Lf
Opis:: Magnetic sponges derived from biocompatible and resorbable polymers are promising materials for medical applications. These materials have been utilised extensively in research applications for the capture of biomolecules and cells, the construction of tissue scaffolds and in regenerative medicine. The object of this study was a polymer scaffold made of polycaprolactone (PCL) containing a 10 wt% amount of nanomagnetite, manufactured in a two-step method. The porosity and morphological parameters were characterised with the use of μ-computer-aided tomography and scanning electron microscopy. Furthermore, the magnetic properties were evaluated. The obtained results confirmed high porosity and the appearance of randomly oriented pores. Moreover, evaluations of the magnetic properties, of both the magnetite nanopowder and the prepared magnetic nanocomposite, were performed. The tests verified the ferromagnetic character of the materials under investigation.
Źródło:: Acta Physica Polonica A; 2014, 125, 4; 891-894
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 58.

Tytuł:: Magneto-Optical Studies of Narrow Band-Gap Heterostructures with Type II Quantum Dots InSb in an InAs Matrix
Autorzy:: Mukhin, M.
Terent'ev, Ya.
Golub, L.
Nestoklon, M.
Meltser, B.
Semenov, A.
Solov'ev, V.
Sitnikova, A.
Toropov, A.
Ivanov, S.
Powiązania:: https://bibliotekanauki.pl/articles/1492858.pdf
Data publikacji:: 2011-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.75.-c
71.70.Ej
78.55.Cr
78.67.Hc
78.20.Ls
75.40.Mg
Opis:: Magneto-optical properties of type II heterostructures with InSb/InAs quantum dots has been studied at external magnetic field applied in the Faraday geometry. The emission polarization degree can be changed in the range from 100% σ-minus to 10% σ-plus due to excitation intensity and temperature variation. The detailed calculation of the band structure within a tight-binding approximation is presented. The simulation of the experimental data reveals that the oscillator strength of the optical transitions involving electrons with the spin oriented along and opposite to the magnetic field vector differs by approximately 1.8 times in the heterostructures under study.
Źródło:: Acta Physica Polonica A; 2011, 120, 5; 868-869
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 59.

Tytuł:: Magnetic Structures in Ultrathin Films and Nanostructures: Simulation
Autorzy:: Lévy, J.-C. S.
Ghazali, A.
Vedmedenko, E. Yu.
Powiązania:: https://bibliotekanauki.pl/articles/2013038.pdf
Data publikacji:: 2000-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.70.Ak
75.50.Tt
75.60.Ch
75.40.Mg
Opis:: In magnetic ultrathin films and dots, competing exchange, anisotropy and dipolar couplings lead to a large variety of magnetic structures. These structures are obtained by means of the Monte Carlo simulations. Three classes of magnetic structures are obtained according to anisotropy-to-dipolar energy ratio: Ising striped structures, XY-spin structures with vortices, and twisted spin phases at the spin = reorientation transition. Domain wall nucleation and motion at the coercive field are also accessible.
Źródło:: Acta Physica Polonica A; 2000, 97, 3; 431-434
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 60.

Tytuł:: Magnetic X-Ray Scattering
Autorzy:: Vettier, C.
Powiązania:: https://bibliotekanauki.pl/articles/1931650.pdf
Data publikacji:: 1994-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.25.+z
75.40.-s
61.10.Dp
Opis:: It was proposed in the 1950's that X-rays could be used to probe magnetization densities. After some experimental demonstrations of the technique, applications have shown that the use of magnetic X-ray scattering combined with synchrotron radiation can lead to important new discoveries in the magnetism of solid materials. Several important features have emerged, especially the resonant magnetic X-ray scattering: large enhancements of scattered intensities, site and species selectivity, X-ray energy and polarization dependence. These properties make it possible to study new phenomena: details of magnetic structures of materials including micro-crystals, new aspects of magnetic phase transitions and surface magnetism.
Źródło:: Acta Physica Polonica A; 1994, 86, 4; 521-535
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 61.

Tytuł:: Magnetic properties of Co-Fe-Si-B microwires
Autorzy:: Kwapuliński, P.
Gieraltowski, J.
Dolabdjian, C.
Stokłosa, Z.
Haneczok, G.
Powiązania:: https://bibliotekanauki.pl/articles/1055108.pdf
Data publikacji:: 2017-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 72.15.Gd
75.30.Gw
75.50.Gg
75.50.Kj
75.90.+w
Opis:: In the paper the magneto-impedance effect in the Co_{68.15}Fe_{4.35}Si_{12.55}B_{15} microwire with diameter of about 100 μ m is carefully studied. The measurements in close contact and contactless geometry were carried out in the static field ranging from 0 to 6 kA/m and frequencies of the alternating field from 20 Hz to 2 MHz. It is shown that the examined microwire shows high anisotropy of soft magnetic properties i.e. the circumferential permeability is at least 7 times higher than the longitudinal one. Moreover, the microwire can be used as highly sensitive magneto-impedance sensor working in contactless geometry especially at fields below 200 A/m.
Źródło:: Acta Physica Polonica A; 2017, 131, 5; 1256-1259
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 62.

Tytuł:: Efficient Calculation of Low Energy Configurations of Nanoparticle Ensembles for Magnetoresistive Sensor Devices by Means of Stochastic Spin Dynamicsand Monte Carlo Methods
Autorzy:: Teich, L.
Schröder, C.
Müller, C.
Patel, A.
Meyer, J.
Hütten, A.
Powiązania:: https://bibliotekanauki.pl/articles/1385684.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Mg
75.75.Jn
75.78.-n
Opis:: We present results of Monte Carlo and stochastic spin dynamics simulations of a magnetic nanoparticle model system based on experimentally produced samples. Thermodynamic investigations as well as spin dynamics studies show characteristic features, both resembling magnetic dipole glass behaviour. While spin dynamics studies at T=0 yield a multitude of low energy configurations, thermodynamic simulations show a clear transition between a paramagnetic and a frozen magnetic state. Moreover, we demonstrate the application of experimentally inspired demagnetization protocols to compute low energy configurations of the systems under consideration efficiently.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 374-376
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 63.

Tytuł:: Strain Designed Magnetic Properties of III-V Magnetic Semiconductors
Autorzy:: Stagraczyński, S.
Jasiukiewicz, C.
Dugaev, V.
Berakdar, J.
Powiązania:: https://bibliotekanauki.pl/articles/1402582.pdf
Data publikacji:: 2015-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Pp
75.30.Gw
75.80.+q
Opis:: We present the theoretical analysis of a possibility of the magnetic anisotropy control using various components of the strain tensor in III-V magnetic semiconductor. We used the Kane model of the valence bands for the numerical simulations of the influence of strain on the Mn doped GaAs valence band structure. Calculating numerically the energy structure of deformed GaMnAs magnetic semiconductor, we also found the total energy of electron system as a function of orientation of the average magnetization vector. Our calculations show how the direction of the magnetization easy axis can be effectively rotated by using different types of deformation.
Źródło:: Acta Physica Polonica A; 2015, 128, 2; 219-221
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 64.

Tytuł:: Some Mesoscopic Rings: Exact Simulations and Experiment
Autorzy:: Kamieniarz, G.
Matysiak, R.
Caramico D'Auria, A.
Esposito, F.
Benelli, C.
Powiązania:: https://bibliotekanauki.pl/articles/2014557.pdf
Data publikacji:: 2000-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Mg
75.40.Cx
75.10.Jm
Opis:: A numerical transfer-matrix approach and an exact diagonalization technique exploiting the point-group symmetry are worked out in the framework of quantum statistical mechanics and group theory for finite rings. They are applied to spin models of the high nuclearity cyclic clusters [Mn(hfac)$\text{}_{2}$NITPh]$\text{}_{6}$ and Ni$\text{}_{12}$(O$\text{}_{2}$CMe)$\text{}_{12}$(chp)$\text{}_{12}$(H$\text{}_{2}$O)$\text{}_{6}$(THF)$\text{}_{6}$. The microscopic parameters of both molecules (J/k$\text{}_{B}$=350±10 K and J/k$\text{}_{B}$=8.5 K±0.5, g=2.23±0.01, respectively) are then obtained from a fit of the theoretical susceptibility curves to the experimental results which are supplemented for Ni$\text{}_{12}$ by new low-temperature measurements.
Źródło:: Acta Physica Polonica A; 2000, 98, 6; 721-727
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 65.

Tytuł:: Soft-Mode vs. Localized Moments Regimes of Spin Fluctuations in Itinerant Electron Magnetism
Autorzy:: Solontsov, A.
Lacroix, C.
Wagner, D.
Powiązania:: https://bibliotekanauki.pl/articles/1964668.pdf
Data publikacji:: 1997-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Gb
75.10.Lp
75.50.Ee
Opis:: An analysis of different regimes of spin fluctuation behaviour in anharmonic itinerant electron magnets is presented basing on the recently worked out soft-mode theory of spin fluctuations.
Źródło:: Acta Physica Polonica A; 1997, 92, 2; 359-362
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 66.

Tytuł:: The Emergence of Subsurface Spin-Waves in fcc (110) Magnetic Films
Autorzy:: Mamica, S.
Puszkarski, H.
Lévy, J.-C. S.
Powiązania:: https://bibliotekanauki.pl/articles/2013076.pdf
Data publikacji:: 2000-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.70.-i
75.40.Gb
75.30.Ds
Opis:: We show that the emergence of subsurface branches in the spin-wave spectra of thin films is due to the deficiency of interactions with next-nearestneighbours, the position vectors of which are oblique to the film surface.
Źródło:: Acta Physica Polonica A; 2000, 97, 3; 483-486
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 67.

Tytuł:: Helical Spin Structures in c-Axis Dy/Y Superlattice
Autorzy:: Seroczyńska, M.
Kociński, J.
Powiązania:: https://bibliotekanauki.pl/articles/1943983.pdf
Data publikacji:: 1996-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.70.Fr
75.70.-i
Opis:: On the basis of Landau's theory of symmetry changes at continuous phase transitions, we have derived the formulae for two incommensurate helical spin structures which are symmetry allowed in Dy/Y superlattice, when the helical axis is parallel to the c-axis of the hexagonal lattice. These structures have different extinction coefficients in their cross-sections for magnetic scattering of neutrons and therefore can be distinguished by experiment. Magnetic satellite peaks around the reciprocal lattice points K + 0 are allowed for only one of these spin structures, namely that inferred from earlier experiments.
Źródło:: Acta Physica Polonica A; 1996, 89, 1; 99-104
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 68.

Tytuł:: Density of States and Indirect Exchange in Metallic Systems
Autorzy:: Hernando, A.
Rojo, J. M.
Gómez Sal, J. C.
Barandiarán, J. M.
Powiązania:: https://bibliotekanauki.pl/articles/1952835.pdf
Data publikacji:: 1996-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.25.+z
75.30.Et
75.50.Bb
Opis:: The relation between the density of states at the Fermi level and the sign of the indirect coupling in metallic systems is revisited in the framework of a simple model recently outlined by the authors. It is shown that high density of states tends to favor ferromagnetic structures. Some examples which support this idea are indicated. Finally we develop a phenomenological explanation for the antiferromagnetic → ferromagnetic transition induced by heating equiatomic FeRh. The transition is analysed in terms of the increase in the density of states produced by the giant volume expansion associated with the ferromagnetic phase.
Źródło:: Acta Physica Polonica A; 1996, 90, 6; 1227-1234
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 69.

Tytuł:: Light Scattering Investigations of Magnetic Anisotropies in Ultrathin Epitaxial Co Films
Autorzy:: Hillebrands, B.
Krams, P.
Fassbender, J.
Mathieu, C.
Güntherodt, G.
Jungblut, R.
Johnson, M. T.
Powiązania:: https://bibliotekanauki.pl/articles/1861065.pdf
Data publikacji:: 1994-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Gw
75.30.Pd
75.30.Ds
78.35.+c
Opis:: Using Brillouin light scattering, the properties of magnetic anisotropies in ultrathin epitaxial Co films grown on single-crystal Cu substrates are investigated. All relevant magnetic anisotropy contributions are determined, in situ in an ultrahigh vacuum system for the (001)-oriented films, as well as ex situ for other film orientations, which are covered with a Cu cap layer. For (001)-oriented films we find a large in-plane anisotropy contribution of fourfold symmetry. For this contribution the volume and the surface part cancel to zero at the same thickness as found for the onset of ferromagnetic order. This finding is indicative for a stabilization of ferromagnetic order in Co/Cu(001) by in-plane anisotropy contributions. In (1 1 13)-oriented films, which are composed of (001)-terraces aligned along the [11̅0]-direction and spaced by 6.5 atomic distances, an additional uniaxial in-plane anisotropy contribution is found which is identified as being of magneto-elastic origin. For (110)-oriented films three ranges of thickness dependence of the in-plane and out-of-plane anisotropy contributions are found which correlate in the thin-film regime with the growth properties. (111)-oriented films show a linear dependence of the perpendicular anisotropy on the reciprocal film thickness over the full investigated thickness range of 2 to 20 Å.
Źródło:: Acta Physica Polonica A; 1994, 85, 1; 179-193
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 70.

Tytuł:: Enhancement of Flux Pinning in the Superconductor-Ferromagnet Bilayer Nb(Co/Pd)
Autorzy:: Syryanyy, Y.
Zhu, L.
Cieplak, M.
Chien, C.
Powiązania:: https://bibliotekanauki.pl/articles/1537204.pdf
Data publikacji:: 2010-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.78.-w
74.78.Fk
74.25.Ha
75.70.Kw
75.70.-i
75.70.Cn
75.78.Fg
Opis:: The magnetometry and the magnetic force microscopy are used to study the influence of the magnetic domain size on the flux pinning in a superconducting/ferromagnetic bilayer (SFB), in which the S layer is niobium and the F layer is a Co/Pd multilayer with perpendicular magnetic anisotropy. The domain size is pre-defined using the angle-dependent demagnetization. The enhancement of pinning is found to be the strongest, up to a factor of 6, for narrow domains and small magnetic fields. This result differs from the behavior observed in the SFB in which the F layer is Co/Pt. The difference may be attributed to the degree of the disorder in the domain pattern.
Źródło:: Acta Physica Polonica A; 2010, 118, 2; 399-401
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 71.

Tytuł:: The Spin-Valve Transistor - a New Magnetoelectronic Device
Autorzy:: Anil Kumar, P. S.
Lodder, J. C.
Powiązania:: https://bibliotekanauki.pl/articles/2011222.pdf
Data publikacji:: 2000-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.70.-i
75.70.Pa
Opis:: A spin-valve transistor showing high sensitivity at low fields was developed. A large magnetocurrent, above 500% is realized by a magnetic field change of 2 to 4 Oe at 80 K. Hot electrons are injected into the spin-valve layer through a Si-Pt Schottky diode. These hot electrons, while traversing through the spin-valve, are spin-dependently scattered. Those electrons with right energy and momentum are collected by a collector (an Au-Si Schottky diode) constituting a collector current. The relative orientation of the magnetic layer in the spin-valve is changed by the application of a magnetic field and causes a change in collector current giving a large magnetocurrent.
Źródło:: Acta Physica Polonica A; 2000, 97, 1; 111-118
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 72.

Tytuł:: Thermodynamic and Magnetotransport Properties of High Quality $Na_{0.77}CoO_{2}$ Single Crystals
Autorzy:: Baran, A.
Zorkovská, A.
Kajňaková, M.
Lin, C.
Feher, A.
Powiązania:: https://bibliotekanauki.pl/articles/1371577.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.20.Hr
75.40.Cx
75.47.-m
Opis:: Heat capacity and electrical resistivity of high-quality $Na_{0.77}CoO_{2}$ single crystals was systematically studied as a function of temperature and magnetic field. Anomalies at 20 K have been observed both in the heat capacity and the electrical resistivity. The broad bump in the heat capacity indicates a smeared magnetic phase transition. Magnetic fields up to 9 T, oriented perpendicularly to the ab plane, reduce the temperature of this anomaly in accordance with the assumption of A-type antiferromagnetic ordering. The low temperature upturn observed in resistivity below 20 K for slow cooling is also suppressed by the magnetic field. This anomaly is probably the consequence of the interplay of several different mechanisms, including the Kondo effect, electron-electron interactions, and electron-phonon scattering.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 360-361
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 73.

Tytuł:: Rigorous Criterion for Reentrance in the Spin-1/2 Ising-Heisenberg Model on Diamond-Like Decorated Bethe Lattices
Autorzy:: Strečka, J.
Ekiz, C.
Powiązania:: https://bibliotekanauki.pl/articles/1506888.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.50.+q
75.10.-b
75.10.Kt
75.40.-s
Opis:: The spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices is exactly solved with the help of decoration-iteration transformation and exact recursion relations. It is shown that the model under investigation exhibits reentrant phase transitions whenever a sufficiently high coordination number of the underlying Bethe lattice is considered.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 725-727
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 74.

Tytuł:: Piezomagnetic Dependences on Magnetic Bias Field of Annealed at 450°C Fe-Cu-Nb-Si-B Alloy
Autorzy:: Kaczkowski, Z.
Milewska, E.
Duhaj, P.
Vlasák, G.
Powiązania:: https://bibliotekanauki.pl/articles/1956531.pdf
Data publikacji:: 1997-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.60.Nt
75.80.+q
75.60.Ch
Opis:: Magnetic field dependences of the piezomagnetic dynamics, magnetomechanical coupling and elasticity moduli in the Fe$\text{}_{73.5}$Cu$\text{}_{1}$Nb$\text{}_{3}$ Si$\text{}_{13.5}$B$\text{}_{9}$ alloy in an as-quenched state and annealed in vacuum for 1 h at 450°C were investigated. The maximum value of the magnetomechanical coupling coefficient was equal to 0.15 for the as-quenched state and 0.7 after annealing at 450°C. The changes of the elasticity moduli (ΔE effect) from about 60 to 180 GPa were observed after annealing at this temperature. These changes are connected with magnetostriction (equal to 25.8×10$\text{}^{-6}$ at saturation), internal stresses, defects, mechanical, magnetic and heat treatment history.
Źródło:: Acta Physica Polonica A; 1997, 91, 2; 487-490
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 75.

Tytuł:: Structural, 1/f Noise and MOKE Characterization of Vicinal La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ Thin Films
Autorzy:: Méchin, L.
Perna, P.
Saïb, M.
Belmeguenai, M.
Flament, S.
Barone, C.
Routoure, J.-M.
Simon, Ch.
Powiązania:: https://bibliotekanauki.pl/articles/2047216.pdf
Data publikacji:: 2007-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Gw
75.47.Lx
75.60.-d
75.60.Jk
75.70.Ak
Opis:: This paper presents some structural, magnetic and electrical properties of 40 nm and 75 nm thick La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ thin films deposited on vicinal SrTiO$\text{}_{3}$(001) substrates. The vicinal angles were 2, 4, 6, 8, and 10º from the [001] direction towards [110]. Standard SrTiO$\text{}_{3}$(001) substrates were used for comparison and for the growth condition optimization. Structural properties were studied by X-ray diffraction, which indicated that the LSMO films grew with their (001) axis coincident with the (001) axis of the substrate. The surface morphology was carefully studied by atomic force microscopy in tapping mode. Very smooth films and regular step-terrace structures on the La$\text{}_{0.7}$Sr$\text{}_{0.3}$MnO$\text{}_{3}$ surfaces could be observed. The root mean square roughness measured in 2μ m×2μ m images was in the 0.130-0.580 nm range for all angles and both thicknesses. Superconducting quantum interference device magnetometer measurements revealed a Curie temperature in the 340-350 K range and magneto-optical Kerr microscopy enabled magnetic domain imaging and hysteresis loop measurements at 300 K. A uniaxial easy magnetization direction was obtained at 300 K for angles above 4º, with the easy axis along the steps. Finally, preliminary 1/f noise measurements were performed at 300 K for bias currents along and perpendicular to the step direction, showing a noise level as low as that we typically measured on standard SrTiO$\text{}_{3}$(001) substrates. All these results are promising for the future realization of room-temperature devices making use of the anisotropy of the magnetization.
Źródło:: Acta Physica Polonica A; 2007, 111, 1; 63-70
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 76.

Tytuł:: Spontaneous Magnetization and Phase Diagrams of the Mixed Spin-1/2 and Spin-S Ising Model on the Bethe Lattice
Autorzy:: Strečka, J.
Ekiz, C.
Powiązania:: https://bibliotekanauki.pl/articles/1032659.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.50.+q
75.10.Hk
75.10.Kz
75.40.Cx
Opis:: The effect of uniaxial single-ion anisotropy on magnetic and critical properties of the mixed spin-1/2 and spin-S (S>1/2) Ising model on a three-coordinated Bethe lattice is rigorously examined with the help of star-triangle transformation and exact recursion relations. In particular, our attention is focused on the ferrimagnetic version of the model, which exhibits diverse temperature dependences of the total and both sublattice magnetizations. It is shown that the critical behavior of the mixed-spin Ising model on the Bethe lattice basically depends on whether the quantum spin number S is integer or half-odd-integer.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 615-617
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 77.

Tytuł:: Magnetization Processes of Hard Magnetic Composites - Monte Carlo Studies aum
Autorzy:: Ziółkowski, G.
Granek, K.
Chrobak, A.
Powiązania:: https://bibliotekanauki.pl/articles/1030445.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Ww
75.60.Ej
02.70.-c
Opis:: In the present work we performed some simulated annealing plus Monte Carlo studies concerning a hard magnetic spherical particles embedded into soft ferromagnetic matrix as well as irregular branches of soft and hard magnetic phases. Magnetization process of such system depends on exchange interactions of soft and hard magnetic object and interface between them. Especially interesting is the comparison of interactions in systems with different, regular and irregular geometry.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 663-665
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 78.

Tytuł:: Spin Hall and Edelstein Effects in Metallic Films
Autorzy:: Borge, J.
Gorini, C.
Vignale, G.
Raimondi, R.
Powiązania:: https://bibliotekanauki.pl/articles/1386604.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 72.25.Mk
75.70.Tj
85.75.-d
Opis:: In an insulator-metal-insulator junction, inversion-symmetry breaking at the interfaces between the 3D metallic film and the top and bottom insulating layers may give rise to a sizeable (Rashba-like) spin-orbit interaction. In this paper we study the spin Hall and Edelstein effects produced by such an interface interaction through a quasiclassical approach. We find that the spin Hall conductivity has a finite value even if spin-orbit interaction with impurities in the bulk of the metallic film is neglected and disorder is properly taken into account. This is in sharp contrast with the case of a strictly 2D metallic layer, in which case impurity scattering is known to completely suppress Rashba-like contributions to the spin Hall conductivity. The non-vanishing of the latter has a profound influence on the Edelstein effect, which we show to consist of two terms, the first with the standard form valid in an exactly 2D system, and a second arising from the presence of the third dimension.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 457-459
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 79.

Tytuł:: Development of Carbon Nanotube Based Reflection Type X-ray Source
Autorzy:: Choi, H.
Kim, J.
Lee, C.
Powiązania:: https://bibliotekanauki.pl/articles/1807922.pdf
Data publikacji:: 2009-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.47.Lx
75.47.Gk
73.50.Fq
Opis:: X-ray imaging technology is a useful and leading medical diagnostic tool for health care professionals to diagnose disease in human body. Carbon nanotube based X-ray source, which we have developed in this study, could be also useful and supply integrated diagnostic X-ray imaging tool in diagnosis. Conventionally, thermionic type of tungsten filament X-ray tube is widely employed in the field of biomedical and industrial application fields. However, intrinsic problems, such as poor emission efficiency, low imaging resolution, and high electrical energy consumption etc., may cause the limitation of using the X-ray tube. To fulfill the current market requirement, specifically for medical diagnostic field, we have developed rather a portable and compact carbon nanotube based X-ray device in which microfocus high imaging resolution can be feasible.
Źródło:: Acta Physica Polonica A; 2009, 115, 6; 1078-1080
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 80.

Tytuł:: Residual stress in Cr₉₉Al₁ polycrystalline thin films
Autorzy:: Mudau, Z.
Sheppard, C.
Prinsloo, A.
Venter, A.
Ntsoane, T.
Fullerton, E.
Powiązania:: https://bibliotekanauki.pl/articles/1047677.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 61.05.C-
68.47.De
75.30.Fv
75.50.Ee
Opis:: The magnetic phase diagram of bulk Cr_{100-x}Al_{x} shows interesting behaviour close to the triple point concentration of x ≈2. Since the magnetic properties of Cr are influenced by dimensionality, stress and strain, this study focussed on the investigation of Cr₉₉Al₁ thin films prepared on fused silica substrates with thicknesses t varying from 29 to 452 nm using sputtering techniques. Resistance measurements covering the temperature range 2 to 400 K did not show any clear anomalies that could be indicative of changes in the magnetic ordering. X-ray diffraction (XRD) and atomic force microscopy (AFM) studies indicate the films are polycrystalline textured and that the 80 nm sample has the smallest grain size. In-plane stresses in these thin films were studied using the specialised XRD ın²ψ-method. The results show that the stress varies with film thickness. The 29 nm sample has stress in the order of 833 MPa and with increasing film thickness the stress reaches 1471 MPa for the 80 nm layer, where after it systematically reduces for the thicker coatings to 925 MPa for the 452 nm film. The highest stress for the Cr₉₉Al₁ thickness sample series is seen in the film with the smallest grain size.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 578-581
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 81.

Tytuł:: Effect of Fe substitution on structural and magnetic properties of NiCr₂O₄
Autorzy:: Mohanty, P.
Prinsloo, A.
Sheppard, C.
Roos, W.
Powiązania:: https://bibliotekanauki.pl/articles/1048307.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Gg
75.60.-d
Opis:: At room temperature, the normal oxide spinel NiCr₂O₄ is tetragonally distorted and crystallizes in the I4₁/amd space group due to cooperative Jahn-Teller ordering driven by the orbital degeneracy of tetrahedral Ni²⁺. The ferrimagnetic Curie temperature (T_{C}) for NiCr₂O₄ is 74 K. The magnetic moments of NiCr₂O₄ are composed of a ferrimagnetic (longitudinal) and an antiferromagnetic (transverse) component. Exchange interaction between the magnetic cations influences the overall magnetic properties of the compound. Present work focuses on the modification of structural and magnetic properties upon substituting Fe at Cr site in NiCr₂O₄ with the motivation of changing the magnetic exchange interaction. In order to do so, single phase Ni(Cr_{0.5}Fe_{0.5})₂O₄ samples were prepared by co-precipitation techniques, while controlling the pH of precipitation. Upon Fe substitution, crystal structure was not affected much contrary to the earlier reports. In order to determine the oxidation state of each elements X-ray photoelectron spectroscopy (XPS) was performed. T_{C} was found to increase dramatically above 300 K, confirmed both from temperature and field dependent dc-magnetization studies.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 574-577
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 82.

Tytuł:: From Magnetic Nanoparticles to Magnetoresistive Biosensors
Autorzy:: Ennen, I.
Albon, C.
Weddemann, A.
Auge, A.
Hedwig, P.
Wittbracht, F.
Regtmeier, A.
Akemeier, D.
Dreyer, A.
Peter, M.
Jutzi, P.
Mattay, J.
Mitzel, N.
Mill, N.
Hütten, A.
Powiązania:: https://bibliotekanauki.pl/articles/1490090.pdf
Data publikacji:: 2012-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 85.70.-w
85.75.-d
75.75.Fk
64.75.Yz
87.85.fk
Opis:: This paper highlights recent advances in synthesis and magnetotransport properties of magnetic Co nanoparticles. It is shown that magnetic Co nanoparticles self-assembled in nanoparticular monolayers revealing giant magnetoresistance similar to granular systems but with additional features resulting from dipolar interactions between small domains of nanoparticles. A spin-valve with one magnetic Co nanoparticular electrode is employed as a model to demonstrate that individual magnetic moments of Co nanoparticles can be coupled to a magnetic Co layer which in turn offers tailoring of the resulting giant magnetoresistance characteristics. In addition, it is demonstrated that combining a magnetic on-off ratchet with magnetic tunneling junctions integrated in the ratchet introduces a new biosensor concept enabling: (1) simultaneous transporting and separating biomolecules, (2) dynamical biomolecule detection when passing magnetic tunneling junctions in a 1D arrangement. It is projected that this biosensor concept could be applied for viruses as well as for bacteria.
Źródło:: Acta Physica Polonica A; 2012, 121, 2; 420-425
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 83.

Tytuł:: The Influence of Annealing Temperature on Magnetic Properties of Vitrovac 6030
Autorzy:: Lachowicz, H. K.
Popławski, F.
Żuberek, R.
Kulik, T.
Ślawska-Waniewska, A.
Kuźmiński, M.
Yu, S. C.
Dynowska, E.
Powiązania:: https://bibliotekanauki.pl/articles/2011100.pdf
Data publikacji:: 1999-09
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Cc
75.50.Kj
75.60.Ch
Opis:: Co-Fe-Mo-Mn-Si-B metallic glass ribbon (Vitrovac 6030) was subjected to the isothermal annealing at temperatures in the range 523-873 K so as to produce a series of samples with gradually coarser microstructure. For this series of samples a giant increase in the coercivity, exceeding three orders of magnitude, is observed. This increase is interpreted in terms of the strengthening of the pinning effect of the nanocrystalline structure on the moving domain walls. It is shown that the anisotropy of the created crystallites is mainly responsible for the increase in the pinning force since the effective anisotropy seen by the wall becomes larger and larger with the gradual increase in the density and size of the grown particles.
Źródło:: Acta Physica Polonica A; 1999, 96, 3-4; 483-494
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 84.

Tytuł:: Magnetic separation of graphite and magnesia
Autorzy:: Uyeda, C.
Hisatoshi, K.
Powiązania:: https://bibliotekanauki.pl/articles/1048225.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.90.+w
Opis:: An ensemble of graphite and magnesia particles was successfully separated into different groups of materials by translating them in an area of magnetic field produced by a NdFeB magnetic-circuit. The absolute value of diamagnetic susceptibility |χ_{dia}| was 2.6×10¯⁷ emu/g in magnesia; previously the separation of diamagnetic grains was possible in materials with |χ_{dia}| values above 5×10¯⁷ emu/g. Terminal velocity observed in a area outside the magnetic field in the magnesia particles having different mass between 0.12 to 0.35 mg, converged to a constant value 1.27±0.05 cm/s; the value was consistent with a theoretical value based on a simple conversion rule between magnetic potential and kinetic energy assumed in the particles. Similar result was obtained for the graphite particles. The technical improvements introduced in the present study to translate the MgO particles can be applied to realize magnetic separation of diamagnetic materials in general.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 694-696
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 85.

Tytuł:: Magnetic Study of Nanocrystalline TiB₂, TiC, B₄C Powders Doped to AISI 316L Austenitic Steel
Autorzy:: Bodziony, T.
Kaczmarek, S.
Biedunkiewicz, A.
Leniec, G.
Figiel, P.
Powiązania:: https://bibliotekanauki.pl/articles/1032403.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 07.55.Jg
75.20.-g
75.50.-y
75.50.Bb
76.30.-v
Opis:: The investigations into ferromagnetic resonance and magnetic susceptibility of nanocrystalline TiB₂, TiC, and B₄C powders (Ti-B-C system) doped to AISI 316L austenitic steel with different amounts (3 vol.%, 5 vol.% and 7 vol.%) have been carried out. The ferromagnetic resonance spectra were recorded in the temperature range from helium up to room temperature. The three tested composite samples contain a number of magnetic phases in different proportions. They reveal a structure originating from several different complex magnetic centers. The composites revealed such magnetic phenomena as paramagnetism, (anti)ferromagnetism, and superparamagnetism. Magnetic susceptibility investigations supported the ferromagnetic resonance studies and their analysis. Magnetic properties of the TiB₂, TiC, B₄C powders doped to AISI steel may play important role in further possible applications of these composite systems.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 62-68
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 86.

Tytuł:: Ferromagnetic Layered Composites. Transfer Matrix Approach
Autorzy:: Puszkarski, H.
Krawczyk, M.
Lévy, J.-C. S.
Mercier, D.
Powiązania:: https://bibliotekanauki.pl/articles/2030419.pdf
Data publikacji:: 2001-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.70.-i
75.30.Ds
02.60.Dc
02.70.Bf
Opis:: A theoretical analysis of spin-wave excitations in a ferromagnetic layered composite (ABAB... ABA; A and B are different homogeneous ferromagnetic materials) is performed by means of the transfer matrix approach. We focus our attention on two features not yet well studied in the present literature, namely, the existence of forbidden energy gaps in the spin-wave mode spectrum, as well as the properties of multilayer spin-wave mode profiles. These features are discussed in relation to several multilayer characteristics, such as the filling fraction, and the exchange or magnetization contrast; surface pinning conditions and dipolar interactions are also taken into account. The existence of forbidden gaps as well as properties of mode profiles are successfully explained by having recourse to an approximate model of independent constituent sublayers. Finally, as a byproduct of our investigation, we ascertain that the conventional test for computational convergence within the finite difference method demands to be completed by symmetry mode profile verification, in addition to standard verification of the frequency convergence alone.
Źródło:: Acta Physica Polonica A; 2001, 100, Supplement; 195-214
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 87.

Tytuł:: The Finite-Size Scaling Study of Five-Dimensional Ising Model
Autorzy:: Merdan, Z.
Aras, N.
Kürkçü, C.
Powiązania:: https://bibliotekanauki.pl/articles/1398913.pdf
Data publikacji:: 2016-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.50.+q
64.60.Cn
75.40.Cx
75.40.Mg
Opis:: The five-dimensional ferromagnetic Ising model is simulated on the Creutz cellular automaton algorithm using finite-size lattices with linear dimension 4 ≤ L ≤ 8. The critical temperature value of infinite lattice is found to be $T^{χ}$ (∞=8.7811 (1) using 4 ≤ L ≤ 8 which is also in very good agreement with the precise result. The value of the field critical exponent (δ =3.0067(2)) is good agreement with δ =3 which is obtained from scaling law of Widom. The exponents in the finite-size scaling relations for the magnetic susceptibility and the order parameter at the infinite-lattice critical temperature are computed to be 2.5080 (1), 2.5005 (3) and 1.2501 (1) using 4 ≤ L ≤ 8, respectively, which are in very good agreement with the theoretical predictions of 5/2 and 5/4. The finite-size scaling plots of magnetic susceptibility and the order parameter verify the finite-size scaling relations about the infinite-lattice temperature.
Źródło:: Acta Physica Polonica A; 2016, 129, 6; 1100-1104
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 88.

Tytuł:: Interval Computations of Ferromagnetic Resonance Conditions in Exchange-Biased Bilayers
Autorzy:: Gutowski, M.
Żuberek, R.
Powiązania:: https://bibliotekanauki.pl/articles/1810606.pdf
Data publikacji:: 2009-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 02.70.-c
73.21.Ac
75.30.Et
75.70.-i
76.50.+g
Opis:: The main purpose of this paper is to promote the use of interval calculus in physics. As an example we use the system consisting of two thin films, one ferromagnetic and another one antiferromagnetic, deposited one atop of the other. We successfully and accurately simulate the positions of resonance fields of such a system, as seen in ferromagnetic resonance experiment. Interval calculations have revealed the presence of 1, 2 and sometimes even 4 distinct equilibrium configurations of the system, all corresponding to the same resonance field, when the field has a component antiparallel to that of cooling field, while only 1 such position when it points in the opposite direction. In both cases only a single resonance line is observed. As an added value we show that the exchange-biased system is in the metastable state, out of true thermodynamical equilibrium.
Źródło:: Acta Physica Polonica A; 2009, 115, 1; 390-392
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 89.

Tytuł:: Biogenic Magnetite Nanoparticle Ensemble Use in MRI Diagnostics
Autorzy:: Strbak, O.
Krafcik, A.
Teplan, M.
Gogola, D.
Kopcansky, P.
Frollo, I.
Powiązania:: https://bibliotekanauki.pl/articles/1202318.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Gg
75.50.Tt
87.61.-c
Opis:: We present a simple analytical tool, which allows the calculation of the MRI diagnostics feasibility of the biogenic magnetite nanoparticles. Elevated levels of these particles are usually linked to the pathological processes, especially to neurodegenerative disorders. We showed theoretically that the biogenic magnetite itself is not sufficient for the non-invasive diagnostics and must be extended with the total iron incorporated in other biological structures.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 388-389
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 90.

Tytuł:: Superconductivity and Quantum Critical Behavior in Cr_{100-z}Os_z
Autorzy:: Prinsloo, A.
Sheppard, C.
Fernando, P.
Powiązania:: https://bibliotekanauki.pl/articles/1398328.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Ee
75.30.Fv
74.70.Ad
74.40.Kb
Opis:: The magnetic phase diagrams of Cr alloys with group-8 metals, such as Re and Ru, show interesting properties. These include quantum critical and superconducting behavior. In order to extend these investigations this paper reports on the physical properties and the magnetic phase diagram of the $Cr_{100-z}Os_{z}$ system, investigated in a concentration range of 2 ≤ z ≤ 30.6. Structural analysis indicate that samples with z<22 have a bcc structure, while those with z>22 include a cubic A15-type structure. Transport and magnetic property measurements indicate that the antiferromagnetic phase disappears at z ≈ 14 and that samples with concentrations z ≥ 12.2 show superconducting behavior. The magnetic phase diagram of $Cr_{100-z}Os_{z}$ is constructed from the Néel and superconducting transition temperatures obtained from various measurements. The commensurate spin-density-wave to paramagnetic phase line decreases sharply for z>4. Fitting parameters of a power law fit to the commensurate spin-density-wave to paramagnetic phase line indicate possible quantum critical behavior. Present results suggest that this phase line terminates in a superconducting dome near a magnetic quantum critical point, similar to that observed in certain heavy fermion systems, but not previously reported for other Cr alloys.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 1132-1134
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 91.

Tytuł:: Magnetic Properties and Structure of Non-Oriented Electrical Steel Sheets after Different Shape Processing
Autorzy:: Bulín, T.
Švábenská, E.
Hapla, M.
Ondrůšek, Č.
Schneeweiss, O.
Powiązania:: https://bibliotekanauki.pl/articles/1032299.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.60.Ej
75.20.En
Opis:: Non-oriented electrical steel sheets are the most often used materials in electrical rotary machines. Raw sheets must be formatted by various methods, e.g., punching, laser, spark or water stream cutting. Basic parameters of magnetic, electrical, and mechanical properties of the sheets are usually obtained from the producer, but namely magnetic properties are changed in dependence on additional machining processes. The aim of this study is to describe changes in magnetic properties after punching, laser or spark cutting of the original sheets M470-50A. The basic information about the structure of the cut edges of samples was obtained by optical microscopy and scanning electron microscopy. For the magnetic measurements toroidal samples were prepared by the mentioned technologies. The magnetic parameters were yielded from the measuring of magnetic hysteresis loops in dependence on saturation fields. The results are discussed from the point of view of applied cutting methods with the aim to obtain the best magnetic parameters and consequently determining the depth of the influenced material. After laser cutting, important decrease in remanence and increase in total losses were observed in comparison with the punched samples.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 819-821
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 92.

Tytuł:: Effect of Granule Shape on the Giant Magnetoresistance for Ferromagnetic Metal-Metal Granular Films
Autorzy:: Wang, C.
Zhang, P.
Zhang, Y.
Rong, Y.
Powiązania:: https://bibliotekanauki.pl/articles/1814027.pdf
Data publikacji:: 2007-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 72.15.Gd
75.47.-m
75.50.-y
Opis:: In order to investigate the effect of granule shape on the giant magnetoresistance, assuming that granular films consist of ellipsoidal ferromagnetic granules embedded in a nonmagnetic metal matrix and the ellipsoidal granules have different demagnetizing factors in three directions, we combined two-current model with the effective medium theory to investigate the effect of granule shape on the giant magnetoresistance. The results revealed that the giant magnetoresistance in granular films depended strongly on the granule shape and was between those for current perpendicular to the plane of the layers and current in the plane of the layers in magnetic multilayers.
Źródło:: Acta Physica Polonica A; 2007, 112, 6; 1231-1238
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 93.

Tytuł:: Influence of Acoustic Phonons on the Magnetic Anisotropy in GaMnAs Magnetic Semiconductors
Autorzy:: Jasiukiewicz, C.
Stagraczyński, S.
Lehmann, D.
Dugaev, V.
Berakdar, J.
Powiązania:: https://bibliotekanauki.pl/articles/1402566.pdf
Data publikacji:: 2015-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Pp
75.30.Gw
77.80.Fm
Opis:: We present a theoretical description of the influence of incoherent acoustic phonons on the magnetic anisotropy of magnetic semiconductors. Our theory is based on the six-band Kane model of the electron energy spectrum describing the valence band with k· p Hamiltonian including the hole-phonon interaction term. We include the effect of incoherent phonons through the hole self-energy in the six-band model, and assume a strong laser-pulse-induced flux of non-equilibrium acoustic phonons. The results of numerical calculations of magnetic anisotropy performed for (GaMn)(AsP) magnetic alloy semiconductors demonstrate the essential role of incoherent phonons.
Źródło:: Acta Physica Polonica A; 2015, 128, 2; 179-181
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 94.

Tytuł:: High Field Magnetization of Sn$\text{}_{1-x}$Gd$\text{}_{x}$Te
Autorzy:: Górska, M.
Anderson, J. R.
Wolters, C.
Łusakowski, A.
Story, T.
Gołacki, Z.
Powiązania:: https://bibliotekanauki.pl/articles/1969093.pdf
Data publikacji:: 1998-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.20.Ck
75.30.Et
Opis:: The magnetization of p-type Sn$\text{}_{1-x}$Gd$\text{}_{x}$Te with x up to 0.045 and the hole concentration, p, varying from 2.7 to 8.3×10$\text{}^{20}$ cm$\text{}^{-3}$ has been measured in magnetic fields up to 27 T, at the temperatures 4.2 and 1.3 K. The data were fitted to a magnetization equation with single-ion and pair terms. From comparison of the exchange parameters determined from the high-field magnetization with those previously obtained from the high-temperature magnetic susceptibility it was found that in samples with p>5×10$\text{}^{20}$ cm$\text{}^{-3}$ the exchange was of a short-range type, while in samples with a lower carrier concentration the long-range exchange mechanism was observed.
Źródło:: Acta Physica Polonica A; 1998, 94, 2; 347-350
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 95.

Tytuł:: Effect of Pressure on Magnetic States of Easy-Plane Antiferromagnets
Autorzy:: Mitsay, Yu. N.
Fridman, Yu. A.
Bairamalieva, G. A.
Alexeev, C. N.
Kochmański, M. S.
Powiązania:: https://bibliotekanauki.pl/articles/1964223.pdf
Data publikacji:: 1997-06
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.30.Kz
75.50.Ee
Opis:: The phase H-P-β diagram of an easy-plane strongly anisotropic antiferromagnet is studied. It is shown that in such a system a realization of the phase with the nonmagnetic order parameter, the so-called quadruple phase, is possible. The realization of this phase is caused by several purely quantum effects, moreover the mechanism of its appearance differs in principle from that of the antiferromagnet or ferromagnet. The possibility of the disappearance of the angular phase (the so-called quadruple ferromagnetic phase) is also shown.
Źródło:: Acta Physica Polonica A; 1997, 91, 6; 1111-1120
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 96.

Tytuł:: Optical Properties of Manganese-Doped Individual CdTe Quantum Dots
Autorzy:: Besombes, L.
Léger, Y.
Maingault, L.
Ferrand, D.
Bougerol, C.
Mariette, H.
Cibert, J.
Powiązania:: https://bibliotekanauki.pl/articles/2043698.pdf
Data publikacji:: 2005-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 78.67.Hc
78.55.Et
75.75.+a
Opis:: The magnetic state of a single magnetic ion (Mn$\text{}^{2+}$) embedded in an individual quantum dot is optically probed using microspectroscopy. The fine structure of a confined exciton in the exchange field of a single Mn$\text{}^{2+}$ ion (S=5/2) is analyzed in detail. The exciton-Mn$\text{}^{2+}$ exchange interaction shifts the energy of the exciton depending on the Mn$\text{}^{2+}$ spin component and six emission lines are observed at zero magnetic field. The emission spectra of individual quantum dots containing a single magnetic Mn atom differ strongly from dot to dot. The differences are explained by the influence of the system geometry, specifically the in-plane asymmetry of the quantum dot and the position of the Mn atom. Depending on both these parameters, one has different characteristic emission features which either reveal or hide the spin state of the magnetic atom. The observed behavior in both zero field and under magnetic field can be explained quantitatively by the interplay between the exciton-manganese exchange interaction (dependent on the Mn position) and the anisotropic part of the electron-hole exchange interaction (related to the asymmetry of the quantum dot).
Źródło:: Acta Physica Polonica A; 2005, 108, 4; 527-540
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 97.

Tytuł:: Magnetic Study of Phases in FeVO₄-Co₃V₂O₈ System
Autorzy:: Guskos, N.
Zolnierkiewicz, G.
Pilarska, M.
Typek, J.
Blonska-Tabero, A.
Aidinis, C.
Powiązania:: https://bibliotekanauki.pl/articles/1030217.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.40.Cx
75.50.Ee
76.30.Fc
Opis:: Magnetic properties of four nFeVO₄/(1-n)Co₃V₂O₈ samples obtained in reactions between FeVO₄ and Co₃V₂O₈ (n = 0.96, 0.86, 0.84 and 0.83, samples designated S1, S3, S4, S5, respectively) have been investigated by DC magnetisation in field cooling and zero-field-cooling modes and EPR. DC magnetic susceptibility showed paramagnetic behavior of all samples in high-temperature range (T > 20 K) and transition to antiferromagnetic state at 16-18 K (depending on sample iron content). Additional magnetic freezing at 8 K was registered for S3-S5 samples containing larger amount of cobalt. The Curie-Weiss law in 100-300 K temperature range indicates that Co²⁺ is in the high-spin state (S = 3/2). From the parameters of the hysteresis loop observed for the samples it was calculated that 0.58% of all magnetic (Fe³⁺, Co²⁺) ions were involved in the ferromagnetic states. EPR spectra of the samples were recorded in high temperature range (T > 90 K). The temperature dependence of the spectral parameters (resonance field, linewidth, integrated intensity) suggested the Fe³⁺ high-spin ions coupled by antiferromagnetic interaction and clusters of ions play major role in EPR spectra.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 24-30
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 98.

Tytuł:: Ferromagnetism in Hubbard Chains
Autorzy:: Cuoco, M.
Noce, C.
Romano, A.
Powiązania:: https://bibliotekanauki.pl/articles/1955828.pdf
Data publikacji:: 1997-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
75.10.Lp
Opis:: We analyze the possible occurrence of ferromagnetism in the Hubbard model, by means of an exact diagonalization study performed on 3- to 8-site chains with periodic boundary conditions. In the case of one hole in the half-filled configuration, we find that the Nagaoka state is reached only in the 3- and in the 4-site case. Ground states characterized by unsaturated ferromagnetism are found when the case of more than one hole is considered.
Źródło:: Acta Physica Polonica A; 1997, 91, 2; 387-390
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 99.

Tytuł:: Nickel/Zinc ratio and lanthanum substitution effect on structural and magnetic properties of nickel zinc ferrites
Autorzy:: Jančárik, V.
Šoka, M.
Ušáková, M.
Harťanský, R.
Powiązania:: https://bibliotekanauki.pl/articles/1053078.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 75.50.Gg
75.30.Cr
61.05.C-
Opis:: Improvement of NiZn ferrites properties by means on Ni/Zn content ratio modification and by partial substitution of Fe³⁺ ions by La³⁺ ions is presented. Ni_{x}Zn_{1-x}Fe₂O₄ and Ni_{x}Zn_{1-x}La_{0.02}Fe_{1.98}O₄ samples of small particles were prepared by self-propagated combustion method. X-ray spectroscopy was used for structural analysis, temperature dependence of magnetic susceptibility was used for evaluation of chemical and phase composition. Analysis showed that pure spinel structure without secondary phase caused by La ions for all values of Ni/Zn content was present. Noticeable growth of the magnetic susceptibility at room temperature was observed with rising of Zn²⁺ ions content.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 693-695
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 100.

Tytuł:: Influence of Carbon on Spin Reorientation Processes in $Er_{2-x}R_xFe_{14}C$ (R~=~Gd, Pr) - Mössbauer and Magnetometric Studies
Autorzy:: Pędziwiatr, A.
Krawiec, K.
Bogacz, B.
Kapusta, Cz.
Przewoźnik, J.
Kaczorowski, D.
Talik, E.
Powiązania:: https://bibliotekanauki.pl/articles/1506592.pdf
Data publikacji:: 2011-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.80.+y
75.25.-j
75.50.-y
75.50.Bb
Opis:: The $Er_{2-x}R_{x}Fe_{14}C$ (R=Gd, Pr) polycrystalline compounds have been synthesized and investigated with $\text{}^{57}Fe$ Mössbauer spectroscopy and magnetic measurements. The spin reorientation phenomena were studied extensively by narrow step temperature scanning in the neighborhood of the spin reorientation temperature. Obtained Mössbauer spectra were analyzed using a procedure of simultaneous fitting and the transmission integral approach. Consistent description of Mössbauer spectra were obtained, temperature and composition dependencies of hyperfine interaction parameters and subspectra contributions were derived from fits and the transition temperatures were determined for all the compounds studied. Initial magnetization versus temperature measurements (in zero and non-zero external field) for $Er_{2-x}Gd_{x}Fe_{14}C$ compounds allowed to establish the temperature regions of reorientation, change of magnetization value during the transition process. The results obtained with different methods were analyzed and the spin arrangement diagrams were constructed. Data obtained for $Er_{2-x}Gd_{x}Fe_{14}C$ were compared with those for $Er_{2-x}Gd_{x}Fe_{14}B$ series.
Źródło:: Acta Physica Polonica A; 2011, 119, 1; 48-51
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

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