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Tytuł:
$\text{}^{57}Fe$ Hyperfine Interactions in the $Sc(Fe_{1-x}Ni_x)_2$ Laves Phases Synthesized under High Pressure
Autorzy:
Wiertel, M.
Surowiec, Z.
Budzyński, M.
Tsvyashchenko, A.
Powiązania:
https://bibliotekanauki.pl/articles/1811581.pdf
Data publikacji:
2008-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.80.+y
77.80.Bh
75.30.Kz
07.35.+k
Opis:
The structural and microscopic magnetic properties of the pseudobinary $Sc(Fe_{1-x}Ni_x)_2$ system prepared under high pressure of 8 GPa were studied by X-ray diffraction and Mössbauer measurements in the range of 0.0 ≤ x ≤ 0.60. The samples for 0.0 ≤ x ≤ 0.10 have the hexagonal C14-type structure and those for 0.30 ≤ x ≤ 0.60 crystallize in the C15-type structure. Both the magnetic hyperfine field on $\text{}^{57}Fe$ and the Curie temperature decrease with the increasing Ni content and the system becomes paramagnetic for x ≈ 0.60 at room temperature. The form and temperature dependences of the Mössbauer spectra for 0.40 ≤ x ≤ 0.50 indicate the coexistence of paramagnetic and ferromagnetic regions in the samples and occurrence of magnetic clusters with a wide distribution of the Curie temperatures. It is interesting that $T_C$ for the compounds obtained under high pressure are by about 100 K smaller in comparison with those for the isostructural samples produced under normal pressure even though interatomic distances are practically equal in the both types of compounds.
Źródło:
Acta Physica Polonica A; 2008, 114, 6; 1517-1527
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D Falicov-Kimball Model in the Perturbative Regime at Finite Temperatures
Autorzy:
Dębski, L.
Powiązania:
https://bibliotekanauki.pl/articles/1810413.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Hf
75.10.Hk
75.30.Kz
75.40.Mg
Opis:
Finite-temperature properties of the Falicov-Kimball model in two approximations were studied in the perturbative regime, i.e. for t/U ≪ 1, where t=1 is the hopping constant and U=10 denotes the Coulomb interaction strength. In our study, we determined the phase diagram of the model in the second order of the perturbation theory, where it reduces to the antiferromagnetic Ising model in the emergent magnetic field. In the fourth order, where our model constitutes the Ising model with more complicated frustrated antiferromagnetic interactions, the phase diagram was established. The Monte Carlo method was employed to investigate the phase transition lines. The existence of stripe ordering at finite temperatures is proved.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 156-158
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Coupled Spin-Electron Diamond Chain with Different Landé g-Factors of Localized Ising Spins and Mobile Electrons
Autorzy:
Torrico, J.
Pereira, M.
Strečka, J.
Lyra, M.
Powiązania:
https://bibliotekanauki.pl/articles/1032419.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Pq
75.30.Kz
75.40.Cx
Opis:
A coupled spin-electron diamond chain with localized Ising spins placed on its nodal sites and mobile electrons delocalized over interstitial sites is explored in a magnetic field taking into account the difference between the Landé g-factors of the localized spins and mobile electrons. The ground-state phase diagram is constituted by two classical ferrimagnetic phases, the quantum unsaturated paramagnetic phase and the saturated paramagnetic phase. Both classical ferrimagnetic phases as well as the unsaturated paramagnetic phase are reflected in a low-temperature magnetization curve as intermediate magnetization plateaus. The unsaturated paramagnetic phase is quantum in its character as evidenced by the fermionic concurrence calculated for a pair of the mobile electrons hopping in between the interstitial sites. It is shown that the magnetic field can under certain conditions induce a quantum entanglement above the disentangled ground state.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 140-142
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Dilute Magnet with Ferro- and Antiferromagnetic Exchange Interactions. The Structural Fluctuations Analysis
Autorzy:
Pikuła, R.
Kirkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813493.pdf
Data publikacji:
2008-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Jk
75.30.Kz
Opis:
We analysed the influence of the fluctuations in distribution of magnetic atoms on the properties of dilute magnets with mixed ferro- and antiferromagnetic exchange interactions. The high- and low concentration approximations were found to give very close results and the most important impact on the physical quantities origins from the lowest, square fluctuations which play the predominant role in the whole range of concentrations of magnetic atoms.
Źródło:
Acta Physica Polonica A; 2008, 113, 2; 669-676
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AC Susceptibility Studies of Phase Transitions and Magnetic Relaxation: Conventional, Molecular and Low-Dimensional Magnets
Autorzy:
Bałanda, M.
Powiązania:
https://bibliotekanauki.pl/articles/1399022.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.40.Gb
75.50.-y
Opis:
The paper presents the review of AC susceptibility measurements in study of magnetic phase transitions and spin dynamics. Examples of several types of phase transitions in conventional and molecular magnets are shown. The phenomenon of magnetic relaxation is briefly ascribed and illustrated with results on relaxation in low-dimensional molecular magnets, such as single molecule magnets, single chain magnets and quasi 1-dimensional systems showing magnetic phase transition to the long-range ordered phase. The following experimental possibilities of the AC technique, which allow to get insight into properties of novel magnetic materials are mentioned: (i) change of the AC field amplitude (in order to distinguish ferro-(ferri) and antiferromagnets); (ii) use of a static field H_{DC} (to conclude on the type of magnetic order and to study the phase diagram); (iii) measurement of nonlinear susceptibilities (to conclude on the type of phase transition); (iv) probing the dependence of both components of susceptibility on frequency of the AC field (to study magnetic relaxation); (v) tests of the DC field effect on the frequency dependence of χ_{AC} (to analyze the possibility of blocking or reentrant spin-glass transition).
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 964-976
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Transport Properties of Carbon-Doped $EuB_6$
Autorzy:
Batkova, M.
Batko, I.
Filipov, V.
Flachbart, K.
Sechovský, V.
Shitsevalova, N.
Šantavá, E.
Šebek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1534309.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
72.15.Gd
75.47.Gk
Opis:
In the presented work we report electrical, magnetic and thermal properties of $EuB_{6-x}C_{x}$ single crystals with an estimated value of x ≈ 0.07. Our studies reveal an antiferromagnetic phase transition at $T_{N}$ ≈ 6.7 K. Electrical resistivity at zero magnetic field shows a pronounced resistivity maximum at $T_{M}$ ≈ 7 K, just above the antiferromagnetic phase transition temperature. With increasing applied magnetic field the maximum moves to lower temperature and becomes totally suppressed at the field of 9 T. Observed magnetoresistance is negative in the whole studied temperature range 2-20 K, yielding a ratio of ρ(0 T, 7 K)/ρ(9 T, 7 K) ≈ 2.5. The origin of such magnetoresistance is associated with formation of mixed magnetic structure in the system due to fluctuation of carbon concentration.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 893-894
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Arbitrarily Weak First Order Phase Transitions in the 3D Standard Ashkin-Teller Model by MC Computer Experiments
Autorzy:
Jeziorek-Knioła, D.
Musiał, G.
Wojtkowiak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1385525.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Hk
75.30.Kz
75.40.Mg
Opis:
The first order phase transition line in the vicinity of the tricritical Ising point region is studied in the 3D standard Ashkin-Teller model on a cubic lattice. The large-scale Monte Carlo computer experiments using the Binder- and Challa-like cumulants, the latter modified by Musial, are proposed and performed. Specific behavior of the Challa-Musial cumulants for weak first order phase transitions is discovered and its interpretation is proposed. The paper proves the arbitrarily weak first order character of phase transitions when approaching to the Ising point.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 327-329
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Atomic Order and the Interaction of Electronic and Magnetic Subsystems in Epitaxial LaSr(Ca)MnO Films
Autorzy:
Okunev, V. D.
Samoilenko, Z. A.
D'yachenko, T.
Abal'oshev, A.
Baran, M.
Gierłowski, P.
Lewandowski, S. J.
Szewczyk, A.
Szymczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/2037110.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.47.Lx
61.50.Ks
Opis:
We have investigated the structure, and electric, optical, and magnetic properties of LaSr(Ca)MnO films containing atomic clusters of various types coherently built into the basic crystallographic matrix. Below the transition to the metallic state, the electrical conductivity of the films is determined by tunneling of charge carriers between metallic clusters. We have found that for each sample there exists a threshold value of magnetic ordering, above which the magnetic subsystem starts to affect actively the film conductivity. The observed increase of conductivity with decreasing temperature is caused by the fact that in the process of magnetic ordering of the samples the cluster size and concentration of metallic phase increase. Experimental results are in agreement with theoretical calculations.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 121-126
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Breakdown of a Magnetization Plateau in Ferrimagnetic Mixed Spin-(1/2,S) Heisenberg Chains due to a Quantum Phase Transition towards the Luttinger Spin Liquid
Autorzy:
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1032725.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Pq
75.10.Kt
75.30.Kz
75.40.Cx
75.60.Ej
Opis:
Magnetization curves of the ferrimagnetic mixed spin-(1/2,S) Heisenberg chains are calculated with the help of density-matrix renormalization group method for several quantum spin numbers S=1, 3/2, 2 and 5/2. It is shown that the ferrimagnetic mixed spin-(1/2,S) Heisenberg chains exhibit irrespective of the spin value S exactly one intermediate magnetization plateau, which can be identified with the gapped Lieb-Mattis ferrimagnetic ground state. The magnetization plateau due to the Lieb-Mattis ferrimagnetism breaks down at a quantum phase transition towards the Luttinger spin liquid, which is characterized by a continuous change of the magnetization with the magnetic field until another quantum critical point is reached at the saturation field.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 624-626
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charge-Ordering and Magnetoelastic Coupling Effects on the Magnetocaloric Properties of Manganites
Autorzy:
Reis, M. S.
Gomes, A. M.
Araújo, J. P.
Tavares, P. B.
Amaral, J. S.
Oliveira, I. S.
Amaral, V. S.
Powiązania:
https://bibliotekanauki.pl/articles/2037124.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
75.80.+q
Opis:
A study of the magnetocaloric properties of La$\text{}_{1-x-y}$Y$\text{}_{y}$Ca$\text{}_{x}$MnO$\text{}_{3}$, La$\text{}_{1-x}$Cd$\text{}_{x}$MnO$\text{}_{3}$, and Pr$\text{}_{1-x}$Ca$\text{}_{x}$MnO$\text{}_{3}$ manganites with ferromagnetic and charge-ordered states is presented. The ferromagnetic lanthanum manganites show a negative entropy change peakΔ S under the application of a magnetic field at the Curie temperature. However, the magnetoelastic coupling effects lead to a first-order paramagnetic-ferromagn etic transition and an increasedΔ S compared to simple ferromagnets. This effect is analyzed in the framework of the Landau theory of phase transitions which shows a comparable influence of the magnetoelastic couplings and the ordinary magnetic ordering effect. The Pr$\text{}_{1-x}$Ca$\text{}_{x}$MnO $\text{}_{3}$ system shows a rich electric and magnetic phase diagram, with a ferromagnetic insulator phase for 0.15
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 163-171
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical Potential as a Detector of Phase Transitions in Solids
Autorzy:
Matlak, M.
Gosławska, E.
Grabiec, B.
Eid, Kh.
Powiązania:
https://bibliotekanauki.pl/articles/2012963.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
75.30.Kz
75.40.Cx
Opis:
We show that the chemical potential exhibits small but distinct kinks at all critical temperatures as the evidence for phase transitions in the electronic system, structural phase transitions included. In the case of, at least, two kinds of interacting electrons average occupation numbers exhibit the same behavior.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 365-368
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical Potential Evidence for Phase Transitions in Magnetic and Superconducting Compounds and Alloys
Autorzy:
Matlak, M.
Pietruszka, M.
Powiązania:
https://bibliotekanauki.pl/articles/2012914.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
75.30.Kz
75.40.Cx
Opis:
We announce that all phase transitions (induced by temperature or concentration) including structural ones and transitions between metastable or "exotic" states can be detected by the chemical potential critical behaviour, as well as, from the average occupation numbers of the electronic system (critical electron redistribution).
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 253-256
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coherent Ferromagnetic Precipitate and Anomalies in the Heat Conduction and Thermopower of Mn$\text{}_{2-x}$Cr$\text{}_{x}$Sb Single Crystals
Autorzy:
Kattwinkel, A.
Kraus, E.
Kleeberg, Ch.
Groń, T.
Bärner, K.
Powiązania:
https://bibliotekanauki.pl/articles/1968922.pdf
Data publikacji:
1998-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
72.15.Eb
72.15.Jf
Opis:
The heat diffusivity D, the electrical resistivity ρ and the thermoelectric power S of tetragonal Mn$\text{}_{2-x}$Cr$\text{}_{x}$Sb single crystals with 0.02 < x < 0.12 have been measured in the temperature range of 90 K < T < 350 K and along different crystal axes. The heat conductivity κ and σ = 1/ρ are anisotropic along the crystal axes a, c with a ratio of 2:1. κ(T) , ρ(T) and S(T) show anomalies at the spin reorientation temperature T$\text{}_{Rm}$ of the matrix (M) Mn$\text{}_{2-x}$Cr$\text{}_{x}$Sb, but also at that of the coherent ferromagnetic precipitate (P) Mn$\text{}_{1.037}$Cr$\text{}_{0.11}$Sb, T$\text{}_{R_{p}}$ which is assigned to variations in the spin dependent scattering at the M /P interfaces via changes in the relative orientation of the magnetization vectors of matrix and precipitate (spin valve effect).
Źródło:
Acta Physica Polonica A; 1998, 93, 5-6; 745-762
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computation of Latent Heat based on the Energy Distribution Histogram in the 3D Ashkin-Teller Model
Autorzy:
Jeziorek-Knioła, D.
Wojtkowiak, Z.
Musiał, G.
Powiązania:
https://bibliotekanauki.pl/articles/1030435.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Hk
75.30.Kz
75.40.Mg
Opis:
The method of computation of the latent heat based on the energy distribution histogram is applied to the standard 3D Ashkin-Teller (AT) model. Similarly as in the original method for the q-state Potts model for strong first order phase transitions, the characteristic histogram with two peaks in the critical region have been observed. Positions of two minima of negative logarithm of internal energy probability for samples of finite size show good linear scalability to the thermodynamic limit. The applicability of this method has been confirmed by proving that the latent heat values are consistent with the ones obtained by us using the analysis of the behavior of the cumulants of the type of Challa and of Lee-Kosterlitz. The presented method is far more efficient than the one based on those cumulants.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 435-437
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of the Spin Wave Phase in Transmission through the Ultrathin Interface between Exchange Coupled Ferromagnetic Materials
Autorzy:
Mailian, M.
Gorobets, O.
Gorobets, Y.
Zelent, M.
Krawczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1030386.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Ds
75.30.Kz
75.78.Cd
Opis:
In this paper, we show analytically and numerically, that the ultrathin metallic layer up to few monatomic layers separating two ferromagnetic media, which are exchange coupled, can effectively change the phase of the reflected or transmitted spin waves. Taking into account ground states with parallel orientations of the magnetization vectors, we developed the analytical model, which shows the possibility of spin-wave phase control by varying the exchange coupling strength between two ferromagnets. Moreover, we demonstrate with micromagnetic simulations that the effect still exists for the spin waves propagating in thin ferromagnetic film during the reflection or transmission from the interface, where interlayer exchange interactions are present.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 480-482
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal Structure and Magnetic Properties of $Tb_{11}O_{20}$
Autorzy:
Baran, S.
Duraj, R.
Hoser, A.
Penc, B.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1400392.pdf
Data publikacji:
2013-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.fm
75.30.Kz
75.40.Gb
75.47.Lx
75.50.Ee
Opis:
Magnetic and neutron diffraction data for $Tb_{11}O_{20}$ compound are reported. This compound crystallizes in a triclinic crystal structure described by the space group P1 and is antiferromagnetic with the Néel temperature 5.1 K.
Źródło:
Acta Physica Polonica A; 2013, 123, 1; 98-100
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal Structure and Magnetic Properties of Pyrrhotite-Type Compounds $Fe_{7-y}V_{y}S₈$
Autorzy:
Selezneva, N.
Ibrahim, P.
Toporova, N.
Sherokalova, E.
Baranov, N.
Powiązania:
https://bibliotekanauki.pl/articles/1397027.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Fn
75.30.Kz
75.50.Gg
Opis:
The pyrrhotite-type compounds $Fe_{7-y}V_{y}S₈$ have been synthesized and studied by means of the X-ray diffraction and magnetization measurements in order to reveal how the substitution of V for Fe affects the crystal structure, phase transition and magnetic properties. The growth of the V content in $Fe_{7-y}V_{y}S₈$ results in changes of the crystal structure and leads to a sharp decrease in the resultant magnetization, non-monotonous change of the coercive field and reduction of the magnetic ordering temperature. Unlike ferrimagnetic ordering in pyrrhotite Fe₇S₈ the compound V₇S₈ is observed to exhibit a Pauli-paramagnetic behaviour.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 450-452
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Cation Substitution on Critical Fields in the n-type $Zn_{x}Sn_{y}Cr_{z}Se_{4}$ Spinel Semiconductors
Autorzy:
Groń, T.
Jendrzejewska, I.
Maciążek, E.
Pacyna, A.
Duda, H.
Zajdel, P.
Krok-Kowalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1791416.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
The ac dynamic magnetic susceptibility was used to study a cation substitution on critical fields in polycrystalline ($Zn_{0.87}Sn_{0.048})Cr_{2.02}Se_{4}$ and $Zn_{0.93}[Cr_{1.95}Sn_{0.05}]Se_{4}$ spinels with tetra- and octahedral coordination of Sn ions, respectively. An increasing static magnetic field shifts the Néel temperature $T_{N}$ to lower temperatures while a susceptibility peak at $T_{m}$ in the paramagnetic region - to higher temperatures. Below $T_{N}$ the magnetic field dependence of susceptibility, $χ_{ac}(H)$, shows two peaks at critical fields $H_{c1}$ and $H_{c2}$. The values of $H_{c1}$ decrease slightly with temperature while the values of $H_{c2}$ decrease strongly with temperature, especially for spinel with octahedral coordination of Sn ions, suggesting a weakness of the ferromagnetic component.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 971-974
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Chemical Disorder on Geometrically Frustrated Kagome Lattice
Autorzy:
Szymczak, H.
Szymczak, R.
Baran, M.
Fink-Finowicki, J.
Krzymanska, B.
Aleshkevych, P.
Jezierski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1812268.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.25.+z
75.30.Gw
75.30.Kz
75.50.-
Opis:
This paper reviews recent progress in the studies of magnetic dilutions on magnetic properties of two frustrated systems: magnetoplumbite-like $SrGa_{12-x}Cr_xO_{19}$ and kagome staircase $Co_3V_2O_8$ doped with Mg ions. In the first group of compounds magnetic properties are determined by magnetic defects arising due to doping. In the case of kagome staircase compounds magnetic dilution suppresses effects of crystal field acting on magnetic ions. In particular, the dilution decreases magnetocrystalline anisotropy and anisotropy of magnetization.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 35-42
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Heavy Ion Irradiation on the Magnetic Properties of CuGeO$\text{}_{3}$
Autorzy:
Gładczuk, L.
Mosiniewicz-Szablewska, E.
Szymczak, R.
Baran, M.
Dąbkowska, H. A.
Choiński, J.
Czosnyka, T.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2013715.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Ee
76.30.Da
Opis:
The influence of heavy ion irradiation on the magnetic properties of the spin-Peierls compound CuGeO$\text{}_{3}$ has been investigated by means of the electron paramagnetic resonance, the spontaneous magnetization, and the low field ac susceptibility. The measurements were performed on the CuGeO$\text{}_{3}$ single crystals before and after irradiation with 80 MeV oxygen ions in the wide temperature range of 2-300 K. It was found that the irradiation induced an increase in the EPR signal intensity, magnetization, and susceptibility of this material. It was also shown that the irradiation does not lead to a decrease in the spin-Peierls transition temperature and to the formation of an antiferromagnetic phase which is expected to appear in disordered spin-Peierls systems.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 871-874
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Neutron Irradiation on the EPR Spectra of CuGeO$\text{}_{3}$
Autorzy:
Mosiniewicz-Szablewska, E.
Gładczuk, L.
Dąbkowska, H. A.
Pytel, B.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2013725.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Ee
76.30.Da
Opis:
The influence of neutron irradiation on the electron paramagnetic resonance spectra of the spin-Peierls compound CuGeO$\text{}_{3}$ was investigated in the wide temperature range 2-300 K. It was found that the irradiation induced appreciable changes in the EPR signal intensity, resonance line width and g-factor of this material. It was also shown that the irradiation leads to a decrease in the spin-Peierls transition temperature. For higher irradiation doses, an antiferromagnetically ordered phase can be observed at lower temperatures. This phase coexists with the spin-Peierls phase. The observed decrease in the spin-Peierls transition temperature after irradiation may be associated with some changes in topological and chemical short-range order or with the transmutation of the fraction of $\text{}^{63}$Cu in the $\text{}^{63}$Cu(n,α)$\text{}^{60}$Co reaction.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 897-900
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Pressure on Magnetic Properties of $(NH_3OH)_2CoF_4$ Fluoro-Metal Complex
Autorzy:
Jagličić, Z.
Zentková, M.
Mihalik, M.
Drofenik, M.
Kristl, M.
Dojer, B.
Kasunič, M.
Golobič, A.
Jagodič, M.
Arnold, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1535548.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
75.30.Cr
75.30.Kz
Opis:
Effect of pressure on magnetic properties of a bulk fluoro-metal complex $(NH_3OH)_2MF_4$ was studied. Magnetization measurements suggest that a ferromagnetic transition at $T_{C1}$ = 47 K is followed by a ferrimagnetic one at $T_{C2}$ = 3 K. Both transition temperatures are pressure dependent with the pressure coefficients $dT_{C1}$/ dp = - 2.6 K/GPa and $dT_{C2}$/ dp = 0.26 K/GPa. The opposite sign of the coefficients is an additional indication of a different nature (ferromagnetic/antiferromagnetic) of these two transitions. The effect of pressure on low field magnetization and exchange bias phenomena is small but still visible.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 1074-1075
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Artykuł
Tytuł:
Effect of the Canting of Local Anisotropy Axes on Ground-State Properties of a Ferrimagnetic Chain with Regularly Alternating Ising and Heisenberg Spins
Autorzy:
Torrico, J.
Lyra, M.
Rojas, O.
de Souza, S.
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1032717.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Pq
75.10.Kt
75.30.Kz
75.40.Cx
75.60.Ej
Opis:
The effect of the canting of local anisotropy axes on the ground-state phase diagram and magnetization of a ferrimagnetic chain with regularly alternating Ising and Heisenberg spins is exactly examined in an arbitrarily oriented magnetic field. It is shown that individual contributions of the Ising and Heisenberg spins to the total magnetization basically depend on the spatial orientation of the magnetic field and the canting angle between two different local anisotropy axes of the Ising spins.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 621-623
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the Jahn-Teller Distortion on Double Exchange Interaction in $La_{0.8}K_{0.2}MnO_3$ Nanoparticles
Autorzy:
Mihalik, M.
Zentková, M.
Vavra, M.
Mihalik Jr., M.
Lazúrová, J.
Girman, V.
Konieczny, P.
Fitta, M.
Il'kovič, S.
Powiązania:
https://bibliotekanauki.pl/articles/1398285.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.47.Lx
75.30.-m
75.30.Kz
Opis:
Electric resistance and effect of hydrostatic pressure on magnetic properties has been studied on the $La_{0.8}K_{0.2}MnO_3$ nanoparticles. Magnetic phase transition is affected by pressure only slightly, the Curie temperature $T_{C}$ decreases with the rate of -1.02 K/GPa, on samples with orthorhombic structure where the Jahn-Teller distortion of lattice is large. On the other hand, $T_{C}$ increases with the rate of 20.1 K/GPa on samples with rhombohedral structure, where the Jahn-Teller distortion of lattice is absent. Insulator type of electrical resistance is characteristic feature of sample with large Jahn-Teller distortion of lattice and insulator-metal transition was observed on samples where the Jahn-Teller distortion is negligible. Our results are in line with theoretical calculation predicting that double exchange interaction is suppressed by the Jahn-Teller distortion.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 875-877
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical and Magnetic Studies of $Zn_{x}Mn_{y}Cr_{z}Se_{4}$ p-Type Semiconductors
Autorzy:
Jendrzejewska, I.
Groń, T.
Duda, H.
Zajdel, P.
Pacyna, A.
Maciążek, E.
Powiązania:
https://bibliotekanauki.pl/articles/1791347.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
The structural, electrical and magnetic investigations carried out on the $Zn_{x}Mn_{y}Cr_{z}Se_{4}$ polycrystals with y = 0.19, 0.29 and 0.38 revealed the spinel structure with the Mn ions occupying tetrahedral sites, p-type conduction with polaronic transport at high temperatures and antiferromagnetic order with a Néel temperature of 20 K and a Curie-Weiss temperature of 103 K. With increasing Mn content in a sample both the effective magnetic moment and the re-entrant temperature increase while the first and second critical fields connected with a metamagnetic transition and the breakdown of the conical spin arrangement decrease, respectively. These results are interpreted in terms of giant cubic anisotropy as well as an effect of Mn impurities on the screw structure of $ZnCr_{2}Se_{4}$.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 913-915
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EMR Study of Electronic and Magnetic Ordering in Doped CaMn$\text{}_{1-x,y}$M$\text{}_{x,y}$O$\text{}_{3}$ (M = Ru, Mo) Perovskites
Autorzy:
Shames, A. I.
Auslender, M.
Rozenberg, E.
Gorodetsky, G.
Martin, C.
Maignan, A.
Powiązania:
https://bibliotekanauki.pl/articles/2043550.pdf
Data publikacji:
2005-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.47.Lx
76.30.-v
76.50.+g
Opis:
X-band electron magnetic resonance measurements of polycrystalline CaMn$\text{}_{1-x,y}$M$\text{}_{x,y}$O$\text{}_{3}$ (M = Ru, 0≤x≤0.5; M = Mo, 0≤y≤0.14) samples were performed at 120 K≤ T≤540 K. The observed anomalies of electron magnetic resonance parameters correlate pretty well with the temperatures of antiferro-, ferromagnetic-like, and orbital/charge-ordering transitions in these systems and specify phase diagrams obtained by other techniques. However, a strong difference between resonant properties of Ru- and Mo-doped series is observed in both paramagnetic and magnetically ordered states. To describe such a difference, the energy bands diagrams, which comprise the deep impurity t$\text{}_{2g}$-like states + e$\text{}_{g}$-like conductive band for CaMn$\text{}_{1-x}$Ru$\text{}_{x}$O$\text{}_{3}$ and shallow impurity states + conductive band, both having e$\text{}_{g}$-like symmetry, for CaMn$\text{}_{1-y}$Mo$\text{}_{y}$O$\text{}_{3}$, are proposed. Specific electrons' contribution to the electron magnetic resonance line width explains concentration and temperature dependences of this parameter in the paramagnetic state in considered systems.
Źródło:
Acta Physica Polonica A; 2005, 108, 2; 235-242
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Field Induced Unusual Magnetic Behavior at Low Temperature in $Pr_{0.67}Ca_{0.33}MnO_3$
Autorzy:
Pektas, M.
Gencer, H.
Izgi, T.
Kolat, V.
Atalay, S.
Powiązania:
https://bibliotekanauki.pl/articles/1207723.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
75.30.Kz
75.30.Sg
Opis:
In this study, magnetic properties of $Pr_{0.67}Ca_{0.33}MnO_3$ compound were investigated in detail. The magnetization versus temperature (M-T) curve showed that this material undergoes a charge order transition at 200 K. A more pronounced FM phase appeared below 56 K. At T = 5 K, a field induced sharp step like magnetisation transition associated with phase separation was observed. However, after application of 7 T magnetic field at 5 K, the magnetic behaviour of sample was changed completely and full FM behaviour was observed. The more interesting is that the sample remains in the FM state and does not retrieve the initial magnetic state until warmed up to charge order transition temperature. Large negative magnetic entropy change (- 26.18 J/(kg K) at 38 K and 5 T) was attributed to step like magnetisation transition.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 217-219
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Field-Induced Magnetic Order in Frustrated $TbBaCo_4O_7$ Single Crystals
Autorzy:
Szymczak, R.
Bludov, A.
Gnatchenko, S.
Barilo, S.
Jezierski, A.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/1536830.pdf
Data publikacji:
2010-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Gw
75.30.Kz
75.60.Ej
75.50.Dd
Opis:
We present results of dc magnetic susceptibility measurements in $TbBaCo_4O_7$ single crystals performed at temperatures in the range 2-300 K and in magnetic fields up to 55 kOe. The results obtained seem to suggest that the ground state of $TbBaCo_4O_7$ is composed of coexisting long-range ordered and short-range ordered clusters and is transformed into a magnetically ordered weak ferromagnetic phase by application high magnetic field along c-axis.
Źródło:
Acta Physica Polonica A; 2010, 118, 2; 299-302
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frustration-Driven Quantum Phase Transition in the 1D Extended Anisotropic Heisenberg Model
Autorzy:
Plekhanov, E.
Avella, A.
Mancini, F.
Powiązania:
https://bibliotekanauki.pl/articles/1813777.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Kz
75.10.Pq
75.40.Mg
Opis:
By using density matrix renormalization group technique we study the 1D extended anisotropic Heisenberg model. We find that starting from the ferromagnetic phase, the system undergoes two quantum phase transitions induced by frustration. By increasing the next-nearest-neighbor interaction, the ground state of the system changes smoothly from a completely polarized state to a next-nearest-neighbor correlated one. On the contrary, letting the in-plane interaction to be greater than the out-of-plane one, the ground state changes abruptly.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 429-432
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ground-State Phase Diagram of a Model FCC Magnet with Modified RKKY Interaction
Autorzy:
Szałowski, K.
Balcerzak, T.
Powiązania:
https://bibliotekanauki.pl/articles/1813773.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.10.-b
75.30.Hx
75.30.Kz
Opis:
The ground-state phase diagram is studied for a diluted model magnet with FCC structure and modified Ruderman-Kittel-Kasuya-Yosida interaction. The modification consists in taking into account the exponential damping for the long-range interaction as well as the nearest-neighbors antiferromagnetic superexchange couplings. The existence of paramagnetic, ordered ferromagnetic and three distinct antiferromagnetic phases is shown. The stability areas of the phases upon the free-carriers concentration are investigated.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 421-424
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Pulsed Magnetic Field Sensor Based on La-Ca-Mn-O Thin Polycrystalline Films
Autorzy:
Balevičius, S.
Žurauskienė, N.
Stankevič, V.
Keršulis, S.
Novickij, J.
Altgilbers, L. L.
Clarke, F.
Powiązania:
https://bibliotekanauki.pl/articles/2041727.pdf
Data publikacji:
2005-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
73.40.Gk
85.70.Ay
61.72.Mm
Opis:
It is demonstrated that polycrystalline La$\text{}_{0.33}$Ca$\text{}_{0.67}$MnO$\text{}_{3}$ thin film sensors can be used to measure pulsed strong magnetic fields with microsecond duration rise and decay times. The response characteristics of these sensors were investigated using 0.7-1.0 ms duration bell-shaped magnetic field pulses of 10-20 T amplitudes and by using special waveform magnetic field pulses with amplitudes of 40 T and decay times of 50μs. The response of these magnetic field sensors was compared with those of conventional loop sensors and Faraday rotation sensors using Bi$\text{}_{12}$SiO$\text{}_{20}$ single crystals as a known standard.
Źródło:
Acta Physica Polonica A; 2005, 107, 1; 207-210
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hopkinson effect in soft and hard magnetic ferrites
Autorzy:
Sláma, J.
Ušáková, M.
Šoka, M.
Dosoudil, R.
Jančárik, V.
Powiązania:
https://bibliotekanauki.pl/articles/1053131.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Gg
75.30.Kz
75.30.Cr
Opis:
The dependences of the susceptibility of selected spinel and hexagonal ferrites on temperature are analyzed. The susceptibility shows a peak just below the Curie temperature T_{C} due to the Hopkinson effect during the heating. The appearance of this effect is associated with a transition from the region of stable magnetization state to superparamagnetic relaxations of the magnetic particles. It is in contrast to other explanations of the Hopkinson effect. These results are compared with measured particles size and with scanning electron microscope micrographs of both types of ferrites.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 762-764
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Ion-Irradiation upon Microstructure and Magnetic Properties of NANOPERM-Type Fe₈₁Mo₈Cu₁B₁₀ Metallic Glass
Autorzy:
Hasiak, M.
Miglierini, M.
Powiązania:
https://bibliotekanauki.pl/articles/1030756.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Bb
75.60.Ej
75.30.Kz
61.80.-x
76.80.+y
Opis:
Microstructure and soft magnetic properties of the Fe₈₁Mo₈Cu₁B₁₀ amorphous alloy in the as-quenched state and after irradiation with N⁺ ions are investigated. CEMS spectra show that the irradiated surface at the air side of the ribbons was significantly affected. On the other hand, no noticeable changes were observed at the opposite wheel side. More deep subsurface regions are also not altered as evidenced by CXMS spectra. Thermomagnetic measurements have shown presence of two magnetically different phases with well distinguished Curie points. They can be ascribed to the amorphous matrix and crystalline phases. The latter were quenched-in during the production process and/or induced by ion bombardment. Curie temperatures of the amorphous matrixes were calculated using the Heisenberg model. For the as-quenched and irradiated ribbons they are of 223 K and 228 K, respectively. The behaviour of coercivity versus temperature was also analysed.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 680-683
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indirect Exchange Interactions in Orthorhombic Lanthanide Aluminates
Autorzy:
Petrov, D.
Angelov, B.
Powiązania:
https://bibliotekanauki.pl/articles/1418289.pdf
Data publikacji:
2012-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.30.Et
Opis:
Magnetic exchange interactions in orthorhombic lanthanide monoaluminates LnAlO_3, Ln = Sm-Yb have been determined semiempirically within the Anderson model of exchange in insulators. The constants of magnetic exchange have been evaluated assuming indirect exchange between pairs of nearest $Ln^{3+}-Ln^{3+}$ ions via $4f^{n} \rightarrow 4f^{n-1}5d$ excitation and ionic polarization. The transfer integrals have been approximated by two-centre overlap integrals between four-term analytical $4f^{n}$ radial wave functions of $Ln^{3+}$ ions. The results have been compared with the available experimental Néel temperatures in the same compounds. It has been found that in most cases the indirect exchange interactions present substantial contributions to the energy of the antiferromagnetically ordered state in $LnAlO_3$.
Źródło:
Acta Physica Polonica A; 2012, 122, 4; 737-740
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of a One-Ion Anisotropy on Stabilization of the Long-Range Magnetic Order in Two-Dimensional Ferromagnet
Autorzy:
Mitsay, Yu. N.
Fridman, Yu. A.
Spirin, D. V.
Kochmański, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/2012959.pdf
Data publikacji:
2000-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.-b
75.30.Kz
Opis:
In the paper the possibility of stabilization of the long-range magnetic order in a two-dimensional ferromagnetic with one-ion easy-plane anisotropy is explored. It is shown that at the presence of a small anisotropy in a two-dimensional ferromagnetic the long-range magnetic order is stabilized by magnetoelastic interaction. If one-ion anisotropy is comparable or even exceeds the exchange interaction in the system there exists a long-range non-vectorial quadrupolar tensorial magnetic order.
Źródło:
Acta Physica Polonica A; 2000, 97, 2; 355-360
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Ball Milling on the Local Atomic Structure of an Amorphous CoFeSiB Alloy
Autorzy:
Bednarcik, J.
Michalik, S.
Kollar, P.
Roth, S.
Powiązania:
https://bibliotekanauki.pl/articles/1534068.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
61.05.cp
64.70.dg
75.30.Kz
Opis:
It follows from experimental observations that ball milling induces substantial changes in an amorphous $Co_{70.3}Fe_{4.7}Si_{10}B_{15}$ (at.%) alloy. X-ray diffraction indicates formation of nanocrystalline bcc-(Co,Fe) phase during ball milling. As a consequence crystallization sequence is altered and the total enthalpy of crystallization reduces with the milling time. Furthermore thermomagnetic measurements reveal that specific magnetization and Curie temperature of amorphous phase are influenced by ball milling.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 825-826
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Co Doping on Crystal and Magnetic Properties of $Gd_2Cu_2In$
Autorzy:
Gondek, Ł.
Szytuła, A.
Kaczorowski, D.
Szewczyk, A.
Gutowska, M.
Tyvanchuk, Yu.
Kalychak, Ya.
Powiązania:
https://bibliotekanauki.pl/articles/1419907.pdf
Data publikacji:
2012-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.Kz
75.50.Ee
Opis:
Physical properties of $Gd_2Cu_{2 - x}Co_{x}In$ (x = 0.1, 0.2, 0.3) samples are investigated. The paper brings results of X-ray diffraction, magnetometric as well as specific heat studies. It was found that only sample with x = 0.1 exhibits desired crystal structure. Other compositions show existence of impurities due to lack of dissolution Co atoms. For $Gd_2Cu_{1.9}Co_{0.1}In$ sample the Curie temperature of 92.5 K was evidenced. Thus, an enhancement of ferromagnetic correlations with comparison to $Gd_2Cu_2In$ sample was evidenced. It was found that $Gd_2Cu_{1.9}Co_{0.1}In$ sample exhibits magnetocaloric effect within broad temperature range.
Źródło:
Acta Physica Polonica A; 2012, 122, 1; 216-219
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Cu, Ga and Au Dopants and Technology Conditions on the Magnetic Interactions in $HgCr_2Se_4$ Single Crystals
Autorzy:
Krok-Kowalski, J.
Władarz, G.
Groń, T.
Duda, H.
Pacyna, A.
Nikiforov, K.
Rduch, P.
Powiązania:
https://bibliotekanauki.pl/articles/1493008.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
For single crystals $HgCr_2Se_4$ doped by nonmagnetic $Cu^{+},$ $Au^{2+}$ and $Ga^{3+}$ ions and single crystals of $HgCr_2Se_4$ matrix growing in different synthesis conditions both the dc and ac magnetic susceptibility as well as the magnetization have been measured. As it follows from the analysis of the obtained results, paradoxically, the dopants strengthen the long range magnetic interactions of the ferromagnetically ordered single crystals under study, evidenced by the higher values of the ordering temperature in comparison with those ones for pure matrix. An influence of the technological processes connected with deficiency and/or excess of Hg on the long range magnetic interactions was not observed.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 970-972
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Hydrostatic Pressure on Magnetic Properties of (Sr,La)(Ru,Cr,Mn)O$\text{}_{3}$
Autorzy:
Piętosa, J.
Wiśniewski, A.
Puźniak, R.
Kolesnik, S.
Majjiga, M.
Dabrowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/2047244.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.Kz
Opis:
An influence of hydrostatic pressure, P, on phase transition temperature, T$\text{}_{C}$, and spontaneous magnetisation, M$\text{}_{0}$, of selected perovskite ruthenates (SrRuO$\text{}_{3}$, La$\text{}_{0.2}$Sr$\text{}_{0.8}$RuO$\text{}_{3}$, SrRu$\text{}_{0.9}$Mn$\text{}_{0.1}$O$\text{}_{3}$, and SrRu$\text{}_{0.9}$Cr$\text{}_{0.1}$O$\text{}_{3}$) was determined to 12 kbar. A decrease in T$\text{}_{C}$ with pressure was found for all of the studied samples. The M$\text{}_{0}$(P) remains unchanged for most of the samples, except for the La$\text{}_{0.2}$Sr$\text{}_{0.8}$RuO$\text{}_{3}$ sample. The weakening of ferromagnetic interactions with increasing pressure is consistent with complex band structure effects related to the modulation of the Ru-O hybridisation by the change of structural distortion.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 159-163
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Pressure on Magnetic Properties of La$\text{}_{1-x}$ Sr$\text{}_{x}$CoO$\text{}_{3-δ}$(x=0.5, 0.67, 1)
Autorzy:
Piętosa, J.
Wiśniewski, A.
Puźniak, R.
Kolesnik, S.
Majjiga, M.
Dabrowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/2046737.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.47.Gk
75.30.Kz
Opis:
Influence of pressure on the phase transition temperature T$\text{}_{C}$ and on the spontaneous magnetisation M$\text{}_{0}$ of highly Sr substituted and oxygen nonstoichiometric La$\text{}_{1-x}$Sr$\text{}_{x}$CoO$\text{}_{3-δ}$ samples was investigated. An increase in T$\text{}_{C}$ and M$\text{}_{0}$ with pressure in investigated samples was found, indicating strengthening of ferromagnetic double exchange interactions, and the expansion of volume of ferromagnetic phase as a~result of enhancement in ferromagnetic interactions in both cluster-glass and long range ferromagnetic states. We did not observe clear correlation between changes in pressure coefficient dT$\text{}_{C}$/dP and changes in the formal oxidation state of the Co ion.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 527-532
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of pressure on the electrical transport properties of carbon-doped EuB₆
Autorzy:
Pristáš, G.
Gabáni, S.
Baťko, I.
Baťková, M.
Orendáč, M.
Gažo, E.
Filipov, V.
Konovalova, E.
Diko, P.
Flachbart, K.
Powiązania:
https://bibliotekanauki.pl/articles/1053101.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.62.Fj
75.30.Kz
Opis:
We have studied the influence of hydrostatic pressure on the electrical resistivity of carbon-doped semimetal EuB₆ which orders ferromagnetically at T_{C}=3.9 K and is intrinsically inhomogeneous due to fluctuations of carbon content. We observed a shift of the low-temperature resistivity maximum from 4.6 K (at 1 bar) to 5.2 K (at 30.3 kbar) with increasing pressure. However, the maximum of the derivative dρ/dT(T), which reveals the temperature of ferromagnetic ordering, does not change its position with increasing pressure. This behaviour is different from stoichiometric EuB₆, where pressure increases the ferromagnetic ordering temperature. The origin of this discrepancy may lie in the increase of volume fraction of the non-ferromagnetic phase with increase of pressure. Additional magnetoresistance measurements at various pressures between 1.5 K and 30 K have shown that with increase of magnetic field the resistivity is monotonically decreasing, and above 1 T a transition to a monotonic resistivity behaviour (dρ/dT(T)>0) is observed. Our results support the picture that carbon-rich regions play a role of "spacers", which prevent the percolation of the ferromagnetic phase.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 982-984
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of spark plasma sintering on microstructure and properties of bulk LaCaSrMnO magnetocaloric materials
Autorzy:
Zmorayová, K.
Antal, V.
Kováč, J.
Diko, P.
Noudem, J.
Powiązania:
https://bibliotekanauki.pl/articles/1053176.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
61.72.-y
75.30.Kz
77.80.B-
81.70.Pg
81.20.Ev
81.30.Fb
Opis:
Polycrystalline La_{0.67}Ca_{0.33-x}Sr_xMnO₃ (x=0.33, 0.03, 0) (LCSM) perovskite samples treated by spark plasma sintering technique were investigated. This study proved influence of the sintering temperature on microstructure of these perovskite ceramics. The thermogravimetric measurements revealed the possibility of increase of oxygen content in studied LCSM samples by additional annealing under oxygen atmosphere and low temperature. Finally, the effect of this annealing on magnetic properties was demonstrated.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 804-806
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Substitution of the Chromium Ions by the Nonmagnetic Sb and Al Ions on the Magnetization Processes in $CuCr_{2}X_{4}$ ( rm X = S, Se) Spinels
Autorzy:
Malicka, E.
Krok-Kowalski, J.
Warczewski, J.
Groń, T.
Duda, H.
Mydlarz, T.
Pawełczyk, M.
Pacyna, A.
Rduch, P.
Władarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1791401.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
Both the dc and ac magnetic susceptibilities as well as magnetization measurements were used to study the influence of the dilution of the magnetic chromium subarray by nonmagnetic antimony and aluminium ions on the magnetization processes for four spinel families under investigation. Substitution of the chromium ions by the nonmagnetic Sb and Al ions in the compounds under study leads to the very hard magnetization in the case of the compounds with Sb and very easy magnetization in the compounds with Al. This effect is connected with the electronic configurations of the Sb and Al ions as well as with ionic radii of these cations.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 967-968
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Temperature on Critical Fields in $Zn_{x}Sb_{y}Cr_{z}Se_{4}$
Autorzy:
Malicka, E.
Groń, T.
Duda, H.
Pacyna, A.
Krok-Kowalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1791371.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
The electrical and complex ac dynamic magnetic susceptibility measurements were used to study an influence of temperature on critical fields in single-crystalline $Zn_{x}Sb_{y}Cr_{z}Se_{4}$ spinel system with y = 0.11, 0.16 and 0.20. The p-type conduction and a shift both of the Néel temperature $T_{N}$ to lower temperatures and a susceptibility peak at $T_{m}$ in the paramagnetic region - to higher temperatures were established. Below $T_{N}$ the magnetic field dependence of susceptibility, $χ_{ac}(H)$, shows two peaks. First peak at the critical field $H_{c1}$ slightly decreases with temperature and remains almost constant as Sb content increases. Second peak at the critical field $H_{c2}$ drops rapidly with temperature and remains almost unchanged as Sb content increases. At $T_{N}$ both critical fields disappear.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 964-966
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Grain Size on the Magnetic Properties of $TbMnO_{3}$
Autorzy:
Bażela, W.
Dul, M.
Dyakonov, V.
Gondek, Ł.
Hoser, A.
Hoffmann, J.
Penc, B.
Szytuła, A.
Kravchenko, Z.
Nosalev, I.
Zarzycki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1431251.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.Cp
61.05.F-
61.05.J-
75.30.kz
75.50.Ee
75.50.-y
Opis:
The magnetic properties including magnetic structure of poly and nano samples of $TbMnO_{3}$ are determined. All the samples investigated are antiferromagnets. In these samples the Mn ad Tb moments order antiferromagnetically at different temperatures and form modulated magnetic structure described by the propagation vector k=($k_{x}$,0,0) with different value of $k_{x}$ for the Mn and Tb sublattices. Comparison of the data for poly and nano samples indicates the decrease of the moment and increase of the $k_{x}$ component of propagation vector in the nano specimens. The wide Bragg peak related to the Tb sublattice suggests that the magnetic order has the claster-like character. The magnetic moments value in both sublattices is smaller, whereas the $k_{x}$ values are larger for nano samples.
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 785-788
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverse magnetocaloric effect in spin-1/2 Fishers super-exchange antiferromagnet
Autorzy:
Gálisová, L.
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1052954.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.30.Et
75.30.Sg
75.30.Kz
Opis:
The isothermal entropy change and the adiabatic temperature change are rigorously calculated for the exactly solved spin-1/2 Fisher's super-exchange antiferromagnet in order to examine magnetocaloric properties of the model in a vicinity of the second-order phase transition. It is shown that the large inverse magnetocaloric effect occurs around the temperature interval T_c(h≠0) < T < T_c(h=0) for any magnetic-field change Δh:0 → h. The most pronounced inverse magnetocaloric effect can be found for the magnetic-field change, which coincides with the critical field of a zero-temperature phase transition from the antiferromagnetically ordered ground state to the paramagnetic one.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 627-629
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large Magnetocaloric Effect in $Nd_{2}Ni_{2}In$
Autorzy:
Maskova, S.
Danis, S.
Llobet, A.
Nakotte, H.
Havela, L.
Powiązania:
https://bibliotekanauki.pl/articles/1368761.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
75.30.Kz
75.30.Sg
Opis:
$Nd_{2}Ni_{2}In$ is an antiferromagnet ($T_{N}$=8 K) with crystal structure equivalent to the Shastry-Sutherland lattice, possibly leading to the magnetic frustration. The AF coupling with moments in the basal plane can be driven by weak magnetic fields (<0.2 T) into the c-axis ferromagnet. The situation leads to large changes of magnetic entropy in fields below 1 T, which makes $Nd_{2}Ni_{2}In$ a candidate for magnetocaloric applications. The entropy change is 9.6 J/(kg K) in fields of 1 T.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 282-283
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low Temperature Magnetic Properties of $Pr_{0.7}(Ca,Sr)_{0.3}CoO_{3}$ Oxides
Autorzy:
Deac, I.
Vlădescu, A.
Balasz, I.
Tunyagi, A.
Tetean, R.
Powiązania:
https://bibliotekanauki.pl/articles/1503539.pdf
Data publikacji:
2011-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
75.30.Kz
75.30.Sg
73.43.Qt
Opis:
We have investigated magnetic and magnetocaloric properties of $Pr_{0.7}(Ca_{1-x}Sr_{x})_{0.3}CoO_{3},$ when the average size of the interpolated cation was changed. $Pr_{0.7}Ca_{0.3}CoO_{3}$ has an orthorhombic Pnma symmetry and it shows a magnetic cluster-glass behavior below 70 K. When Sr partially replaces Ca in this compound, its magnetic properties are improved, and it begins to have ferromagnetic-like behavior. The magnetic transition temperature, gradually, increases with increasing Sr content, up to 170 K, for x=1. The electrical conduction also improved when Sr content increased. All the samples show negative magnetoresitance. Magnetic entropy change $\Delta S_{M}$ was estimated from isothermal magnetization data. We have found that it had higher values for the samples with x>0.5, around 1 J/kg K for Δ B=4 T, with reasonable good relative cooling power.
Źródło:
Acta Physica Polonica A; 2011, 120, 2; 306-310
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnet with Ferromagnetic Nearest-Neighbor and Antiferromagnetic Next-Nearest-Neighbor Exchange Interactions
Autorzy:
Szymczak, R.
Szymczak, H.
Kamieniarz, G.
Szukowski, G.
Jaśniewicz-Pacer, K.
Florek, W.
Maltsev, V.
Babonas, G.
Powiązania:
https://bibliotekanauki.pl/articles/1808031.pdf
Data publikacji:
2009-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.40.Cx
75.50.Ee
75.30.Gw
75.30.Et
75.30.Kz
Opis:
Magnetic properties of $Pb[Cu(SO_4)(OH)_2]$ (linarite) natural single crystals were studied by magnetization and specific heat measurements. The angular dependences of magnetization were revealed which correlated with the regularities of the crystal structure. At about 2.8 K this quasi-one-dimensional Heisenberg system undergoes a phase transition to the long-range antiferromagnetic order with antiparallel magnetic moments aligned probably along the b-axis. The antiferromagnetic order is evidenced by the metamagnetic transition and pronounced λ-type anomaly at $T_N$ in the specific heat. Using phenomenological modeling based on a quantum transfer-matrix method, we argue that at higher temperatures linarite is a quasi-one-dimensional system with competing ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor exchange interactions.
Źródło:
Acta Physica Polonica A; 2009, 115, 5; 925-930
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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