Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Twardowski, J." wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 28
Tytuł:
Observation of Magnetic Anisotropy in GaN:Cr Single Crystals
Autorzy:
Gosk, J.
Boćkowski, M.
Kowalski, G.
Grzegory, I.
Szczytko, J.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1403624.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
75.30.Gw
75.50.Pp
75.10.Dg
Opis:
Magnetic properties of bulk wurtzite GaN:Cr single crystals were studied with the magnetic field applied parallel and perpendicular to the crystal wurtzite c-axis. Structure of the crystal was examined by the X-ray diffraction method. Strong anisotropy of magnetization at low temperatures (2-10 K) was observed. The experimental data suggest Cr to be in nonspherical $d^4$ configuration.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1007-1009
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Epitaxial Strain on Magnetic Anisotropy in (Ga,Mn)As
Autorzy:
Juszyński, P.
Wasik, D.
Gryglas-Borysiewicz, M.
Przybytek, J.
Szczytko, J.
Twardowski, A.
Sadowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1403622.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.47.-m
Opis:
Two (Ga,Mn)As samples having different magnetic anisotropy (one with in-plane easy axis and another one with out-of-plane easy axis) were studied by means of magnetotransport experiments. Anisotropy field B_{A} was determined for both samples as a function of temperature. For the sample having in-plane easy axis, an inversion of the direction of planar Hall effect hysteresis was observed upon increase of temperature. This result was simulated using the Stoner-Wohlfarth model.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1004-1006
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetooptical Properties of GaAs:Mn
Autorzy:
Szczytko, J.
Stachow, A.
Mac, W.
Twardowski, A.
Becla, P.
Tworzydło, J.
Powiązania:
https://bibliotekanauki.pl/articles/1952188.pdf
Data publikacji:
1996-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.Ls
Opis:
Magnetoreflectance from GaAs:Mn was measured in the free exciton range for B ≤ 5 T and T = 2.0 K. Combining optical results with magnetization data the value for the exchange parameter N$\text{}_{0}$α-N$\text{}_{0}$β =-(2.3 ± 0.6) eV was obtained. Assuming that N$\text{}_{0}$α ≈ +0.2 eV, the ferromagnetic p-d exchange interaction was found with the magnitude N$\text{}_{0}$β ≈ +2.5 eV.
Źródło:
Acta Physica Polonica A; 1996, 90, 5; 951-954
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetization of GaMnN Ceramics Prepared from Nanopowders by an Anaerobic Synthesis and High-Pressure High-Temperature Sintering
Autorzy:
Gosk, J.
Drygaś, M.
Janik, J.
Gierlotka, S.
Pałosz, B.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1398535.pdf
Data publikacji:
2016-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Mm
81.07.Wx
81.07.-b
Opis:
Herein, we report a study on magnetic properties of GaMnN ceramics prepared by no additive high-pressure high-temperature sintering of a range of nanopowders, the latter made via an anaerobic synthesis method in the Ga/Mn bimetallic system at various nitridation temperatures and different levels of initial Mn concentration. Measurements of the magnetization as a function of temperature and magnetic field for the ceramics and parent nanopowders showed a typical paramagnetic behavior. Antiferromagnetic interactions between Mn-ions incorporated in the GaN lattice, GaMnN, were revealed and shown to be much stronger in the ceramics than in the respective nanopowders. In addition, in all of these materials an antiferromagnetic contribution originating from a residual Mn₂SiO₄ by-product was also observed. The highest calculated Mn concentration in the nanopowders reached 3.4 at.%. Complex mixtures of gallium nitride polytypes with multimodal particle size distributions in the nanosized range (small nano: 2-8 nm, large nano: 35-60 nm) were converted upon sintering to the single hexagonal GaN phase with average crystallite sizes of 40-80 nm and higher. For the optimal 700°C-treated materials, the Mn concentration in the parent GaMnN nanopowder was 3.2 at.% whereas in the derived ceramics it amounted to 5.5 at.%. At the same time, contributions of the adventitious Mn₂SiO₄ by-product significantly decreased upon sintering.
Źródło:
Acta Physica Polonica A; 2016, 129, 1a; A-103-A-106
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconductivity Study of GaN Highly Doped by Transition Metals
Autorzy:
Gosk, J.
Boćkowski, M.
Tokarczyk, M.
Kowalski, G.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1399142.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.25.Ha
74.70.-b
74.25.Dw
75.50.-y
61.72.Dd
81.10.Dn
Opis:
GaN:Cr and GaN:Fe single crystals as well as GaN:Mn micropowders highly doped by transition metals were grown to investigate low temperature superconductivity. Magnetic measurements revealed type I superconductivity with $T_{C} ≈ 6 K$ and $H_{C} ≈ 600 Oe$, identical for all compounds and also identical to that observed before in GaP:Cr and GaAs:Cr. The presence of amorphous inclusions of gallium may explain existing superconductivity as a result of a phase transition leading to β-Ga during cooling down of the sample. Since the observed parameters are close to those characteristic for superconducting Ga(II) this possibility could not be ruled out.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 877-880
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MnAs Nanocrystals Embedded in GaAs
Autorzy:
Kwiatkowski, A.
Wasik, D.
Kamińska, M.
Twardowski, A.
Dłużewski, P.
Borysiuk, J.
Sadowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1811951.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.20.-g
75.75.+a
Opis:
Magnetic properties of MnAs nanocrystals embedded in GaAs are analyzed in the frame of phenomenological model proposed by Sasaki for ferritin superparamagnets. Our calculations explain qualitatively experimental data of magnetization versus temperature, obtained according to zero-field-cooled and field-cooled protocols. They show dynamics of magnetization of MnAs nanocrystals in range of temperature from 10 K to 320 K. There is transition from state in which very slow dynamics is observed (frozen state) to state in which dynamics is fast (quasi-superparamagnetic state).
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1207-1211
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MnAs Nanocrystals Embedded in GaAs
Autorzy:
Kwiatkowski, A.
Borysiuk, J.
Bożek, R.
Wasik, D.
Kamińska, M.
Sadowski, J.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2046925.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.46.+w
61.82.Fk
68.37.Rt
68.37.Lp
74.25.Ha
Opis:
We report on cross-sectional transmission electron microscopy and magnetic force microscopy studies performed on self-organized MnAs nanoclusters embedded in GaAs. It was found that 10÷20 nm large MnAs ferromagnetic nanocrystals were formed during rapid thermal annealing of Ga$\text{}_{1-x}$Mn$\text{}_{x}$As layers at 600ºC, leading to magnetic contrasts in magnetic force microscopy images.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 233-236
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation of Superconductivity in Highly Cr-Doped GaP Single Crystals
Autorzy:
Gosk, J. B.
Strzelecka, G.
Kowalski, G.
Hruban, A.
Kamińska, M.
Twardowski, A.
Gronkowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/2046913.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.10.+v
75.50.Pp
61.72.Vv
61.72.Dd
81.10.Dn
Opis:
Studying bulk GaP, highly doped with Cr, and searching for possible ferromagnetic semiconductor in view of spintronic applications, we found superconducting behavior of this material unexpectedly. Magnetization techniques and X-ray diffraction were applied to study these crystals. Magnetization revealed superconducting features up to about 6 K and X-ray studies showed that superconductivity might be related to small size Cr precipitates.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 189-193
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetric Magnetization Reversal in the Exchange-Biased MnO/(Ga,Mn)As Heterostructure Studied by Ferromagnetic Resonance
Autorzy:
Dziatkowski, K.
Ge, Z.
Liu, X.
Furdyna, J. K.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2046987.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
76.50.+g
75.30.Gw
75.70.Cn
Opis:
We report ferromagnetic resonance study of the magnetization reversal in the exchange-coupled MnO/(Ga,Mn)As system. The low-field parts of ferromagnetic resonance spectra measured along [1/10] and [100] directions of (Ga,Mn)As were combined into hysteresis loops, which under field-cooling conditions similarly to SQUID loops are shifted toward negative magnetic fields. The magnetization reversal process revealed by the loops occurred remarkably asymmetric for both sample configurations.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 319-324
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Artykuł
Tytuł:
Specific Heat of Cr-Based Semimagnetic Semiconductors
Autorzy:
Twardowski, A.
Eggenkamp, P.
Mac, W.
Swagten, H. J. M.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1929660.pdf
Data publikacji:
1993-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
71.70.Ch
71.70.Ej
Opis:
Specific heat of ZnCrSe and ZnCrS was measured for 1.5 < T < 10 K and B < 3 T. The data were interpreted using "crystal field model" taking into account tetrahedral crystal field, tetragonal Jahn-Teller distortion and spin-orbit interaction.
Źródło:
Acta Physica Polonica A; 1993, 84, 3; 563-565
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-Field EPR of Zn$\text{}_{1-x}$Cr$\text{}_{x}$Te
Autorzy:
Boonman, M. E. J.
Mac, W.
Wittlin, A.
Twardowski, A.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933865.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
76.30.Fc
78.30.Fs
Opis:
High magnetic field electron paramagnetic resonance experiments have been performed on Zn$\text{}_{1-x}$Cr$\text{}_{x}$Te covering the energy range 1-7 cm$\text{}^{-1}$ in fields up to 20 T at T = 1.2 K. The static magnetic field was oriented along the (100), (110) and (111) crystallographic axes of the sample. Pronounced absorption lines for intra-chromium transitions have been observed for these different orientations, revealing a strong anisotropy due to a static Jahn-Teller distortion. The measured low energy level structure of the Cr$\text{}^{++}$ ion can be described by a cubic crystal field model including this distortion of the Cr centers.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 829-832
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EPR Spectra of Multispin Systems. Application to Poly-m-p-Aniline
Autorzy:
Juszyński, P.
Twardowski, A.
Gosk, J.
Kulszewicz-Bajer, I.
Pawłowski, M.
Dziatkowski, K.
Szczytko, J.
Powiązania:
https://bibliotekanauki.pl/articles/2048138.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.70.-c
75.10.-b
Opis:
In this communication we present NiceMagnetic, software for simulations and analysis of EPR spectrum and SQUID measurements. Systems of arbitrary number N of spin-only magnetic moments (S ≤ 0 and L = 0) were considered within the lines of the Heisenberg and Zeeman Hamiltonians. Effective algorithms used for the computations are discussed. This includes modified secant method adapted to calculate resonance fields with demanded precision. Finally, application of NiceMagnetic to experimental SQUID magnetization and EPR spectra of poly-m-p-aniline, one of recently synthesized high spin polymers containing unpaired electrons will be presented. As a result, exchange integral between electron and nitrogen nuclei spins (ligand hyperfine interaction) J = 6.3 × 10$\text{}^{-4}$ cm$\text{}^{-1}$ was estimated.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 717-719
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of the Spin-Dependent Potential fluctuations on Free Exciton Zeeman Splitting of Zn$\text{}_{1-x}$Mn$\text{}_{x}$Se
Autorzy:
Herbich, M.
Mac, W.
Stachow, A.
Twardowski, A.
Tworzydło, J.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1950805.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.Ls
Opis:
Magnetoreflectance of free exciton and magnetization in Zn$\text{}_{1-x}$Mn$\text{}_{x}$Se (0.0007 < x < 0.12) were measured. The evaluated proportionality factor between the exciton splitting and the magnetization showed a strong concentration dependence. This effect cannot be explained within the mean field approximation and the virtual crystal approximation and it was described within the model including chemical and magnetic disorder.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 813-816
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exchange Interaction in ZnCrSe Semimagnetic Semiconductor
Autorzy:
Mac, W.
Nguyen, The Khoi
Twardowski, A.
Gaj, J. A.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1924249.pdf
Data publikacji:
1992-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
Opis:
Magnetoreflectance and magnetization of ZnCrSe were measured for B ≤ 5 T and T = 2 K. A linear dependence between exciton splitting and magnetization was found. The s, p-d exchange parameter was estimated: N$\text{}_{0}$α-N$\text{}_{0}$β=0.67eV.
Źródło:
Acta Physica Polonica A; 1992, 82, 5; 902-904
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 28

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies