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Tytuł:
Monte Carlo Study of a Spin-3/2 Blume-Emery-Griffiths Model on a Honeycomb Lattice
Autorzy:
Žukovič, M.
Jaščur, M.
Powiązania:
https://bibliotekanauki.pl/articles/1199541.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.30.Kz
75.50.Lk
Opis:
We study the phase diagram of the spin-3/2 Blume-Emery-Griffiths model on a honeycomb lattice by Monte Carlo simulations in order to verify the presence of some peculiar features predicted by the effective field theory (EFT) with correlations. The locations of the order-disorder phase boundaries are estimated from thermal variations of the magnetic susceptibility curves. It is found that for positive values of the biquadratic interactions the critical boundary shows a discontinuous character as a function of the single-ion anisotropy strength, in line with the EFT expectations. However, for negative values of the biquadratic interactions the step-like variation of the critical frontier predicted by EFT was not reproduced.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 36-37
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ordering in Triangular Lattice Ising Antiferromagnet Due to Dilution and Magnetic Field
Autorzy:
Žukovič, M.
Borovský, M.
Bobák, A.
Powiązania:
https://bibliotekanauki.pl/articles/1506982.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.30.Kz
75.50.Ee
75.50.Lk
Opis:
We study effects of an external magnetic field and random site dilution on the magnetic ordering in the geometrically frustrated triangular lattice Ising antiferromagnet by the use of an effective-field theory with correlations. In particular, we find that already a small amount of the quenched dilution locally relieves the frustration which in the presence of the external field is manifested by multiple splitting of a broad frustration-induced 1/3 magnetization plateau. Depending on the field strength, the dilution can either decrease or increase the magnetization or even change its effect from decreasing to increasing.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 740-741
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:
Magnetic Properties of $NdFe_{0.9}Mn_{0.1}O_{3}$
Autorzy:
Zentková, M.
Lazúrová, J.
Kováč, J.
Mihalik, M.
Briančin, J.
Fitta, M.
Kusigerski, V.
Powiązania:
https://bibliotekanauki.pl/articles/1371226.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.47.Lx
75.30.-m
75.30.Kz
75.30.Et
75.30.Cr
Opis:
In our paper we study effect of Mn for Fe substitution on magnetic properties of $NdFe_{x-1}Mn_{x}O_{3}$ compounds for x=0 and 0.1, which have been grown by the OFZ technique. The Néel temperature decreases from $T_{N1}$=691 K to $T_{N1}$=621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x=0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at $T_{sh}$ to higher temperatures. Another anomaly is generated by doping at $T_{max}$=11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 306-307
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transitions Induced in HoCo$\text{}_{3}$Ni$\text{}_{2}$ Single Crystals
Autorzy:
Zawadzki, J.
Ballou, R.
Gorges, B.
Szymczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/1928269.pdf
Data publikacji:
1993-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Gw
75.30.Kz
75.50.Gg
75.60.Ej
Opis:
The magnetic studies of temperature and field induced phase transitions were performed on single crystals of HoCo$\text{}_{3}$Ni$\text{}_{2}$ compound. The rotational-type spin reorientation was found between T$\text{}_{SR1}$ = 160 K and T$\text{}_{SR2}$ = 200 K. In the vicinity of T$\text{}_{SR1}$ two different field induced transitions were observed: the first order moment reorientation type transition in the basal plane and the spin reorientation from the easy plane to the c-axis with simultaneous increase in spontaneous magnetization. The intersublattice molecular field coefficient as well as the magnetization anisotropy of Ho sublattice were determined. The observed magnetic behaviour was analysed within the framework of the spin-reorientation model, taking into account the change of the intrinsic states of rare-earth ions caused by their huge anisotropy energy. The thermal variation of the anisotropy constants of the studied compound is also presented.
Źródło:
Acta Physica Polonica A; 1993, 83, 2; 209-218
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of $Tb_{1 - x}Y_{x}$ NiIn System
Autorzy:
Zarzycki, A.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1419576.pdf
Data publikacji:
2012-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.Cx
75.40.Gb
75.47.Np
Opis:
Polycrystalline samples of $Tb_{1 - x}Y_{x}NiIn$ (x = 0.2 and 0.4) were prepared and studied by powder X-ray diffraction and AC and DC magnetic measurements. The compounds crystallize in the hexagonal ZrNiAl-type structure. At low temperatures the ferromagnetic properties are detected. With increasing Y content a change in the magnetic properties, decrease of the Curie temperatures and magnetic moment in the ordered state are observed.
Źródło:
Acta Physica Polonica A; 2012, 122, 2; 382-383
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Magnetic Properties of $(Cu_{x}Mn_{1-x})_3[Cr(CN)_6]_2$ · $zH_2O$ Complexes
Autorzy:
Vavra, M.
Antoňák, M.
Jagličić, Z.
Mihalik, M.
Csach, K.
Zentková, M.
Powiązania:
https://bibliotekanauki.pl/articles/1535120.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.30.Cr
Opis:
Magnetization measurements were performed on the $(Cu_{x}Mn_{1-x})_3[Cr(CN)_6]_2$ · $zH_2O$ molecule-based magnets where x=0.0, 0.2, 0.25, 0.3, 0.35 0.4, 0.6, 0.8 and 1.0. Both the Curie temperature and saturated magnetization at first decrease with increasing value of x reaching the minimal value of $T_{C}$ = 49.7 K and 0.17 $μ_{B}$ for x=0.2 and then increase with substitution. The pronounced hysteretic behavior between zero-field cooled and field cooled regimes was observed for all samples. Magnetization changes the sign of magnetic polarization in zero-field cooled magnetization curve at the compensation temperature $T_\text{comp}$ = 16 K for sample with x = 0.4. Our results indicate that the system behaves as mixed-ferri-ferromagnetic system.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 998-999
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties $RNi_5Sn$ (R = Pr, Nd) Compounds
Autorzy:
Tyvanchuk, Yu.
Romaka, L.
Szytuła, A.
Duraj, R.
Zarzycki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1400410.pdf
Data publikacji:
2013-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.40.Gb
75.50.Ee
Opis:
X-ray diffraction and magnetic measurements of $RNi_5Sn$ (R = Pr, Nd) compounds are reported. These compounds crystallize in the hexagonal $CeNi_5Sn$-type structure. Magnetic data indicate that both compounds are antiferromagnet with the Néel temperatures $T_{N}$ equal to 24 K (R = Pr) and 8.8 K (R = Nd). The magnetic data below $T_{N}$ suggest the complex magnetic order.
Źródło:
Acta Physica Polonica A; 2013, 123, 1; 145-147
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of $Ho_{5}Ni_{2}In_{4}$
Autorzy:
Tyvanchuk, Yu.
Penc, B.
Szytuła, A.
Zarzycki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1538371.pdf
Data publikacji:
2010-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
Opis:
X-ray diffraction and magnetic measurements of $Ho_{5}Ni_{2}In_{4}$ are reported. This compound crystallizes in the orthorhombic $Lu_{5}Ni_{2}In_{4}$-type structure. Magnetic data indicate ferromagnetic properties below $T_c$ = 30 K.
Źródło:
Acta Physica Polonica A; 2010, 117, 4; 599-600
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Chemistry and Magnetic Properties of $R_2Ni_{2-x}In$ (R=Gd-Er, x=0.22 or 0.3) Compounds
Autorzy:
Tyvanchuk, Yu.
Baran, S.
Jaworska-Gołąb, T.
Duraj, R.
Kalychak, Ya.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1489895.pdf
Data publikacji:
2012-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
61.10.-i
61.66.Dk
75.40.Gb
75.50.Ee
Opis:
X-ray diffraction and magnetic measurements of $R_2Ni_{2 - x}In$ (R = Ho, Dy, x = 0.3 and R = Gd, Tb, Er, x = 0.22) compounds are reported. The compounds crystallize in the tetragonal $Mo_2FeB_2$-type crystal structure (space group P4/mbm). Magnetic measurements reveal antiferromagnetic order with the Néel temperatures $T_{N}$ equal to 26.4 K (Gd), 20.2 K (Tb), 8.3 K (Dy), 7.1 K (Ho), and 6.3 K (Er). For R = Gd, Tb and Er an additional phase transition below $T_{N}$ is observed at 13.5, 13.1, and 5.0 K, respectively.
Źródło:
Acta Physica Polonica A; 2012, 121, 3; 678-681
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orbital Correlations and Magnetic Phase Transitions in Lightly Doped La$\text{}_{0.88}$MnO$\text{}_{x}$ and LaMn$\text{}_{0.94}$O$\text{}_{y}$ Manganites
Autorzy:
Troyanchuk, I. O.
Khomchenko, V. A.
Tovar, M.
Szymczak, H.
Bärner, K.
Powiązania:
https://bibliotekanauki.pl/articles/2037044.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.47.Lx
61.50.Ks
Opis:
The results of X-ray and neutron diffraction study as well as the elastic, magnetic, and electrotransport properties of La$\text{}_{0.88}$MnO$\text{}_{x}$ (2.82≤ x≤2.96) and LaMn$\text{}_{0.94}$O$\text{}_{y}$ (2.91≤ y≤3.00)$ manganites have been presented. Under oxygen doping, the transitions from antiferromagnetic to ferromagnetic or spin-glass state are observed for La-deficient and La-excessive series, respectively. These transitions have been found to correlate with the change of the type of Jahn-Teller distortions from static to dynamic ones. The dynamic orbital correlations favor a ferromagnetic state, while an A-type antiferromagnetic state is typical of the static Jahn-Teller distortions. It is argued that the canting magnetic structure in manganites is not realized. The transition to a ferromagnetic or spin-glass state occurs via the formation of inhomogeneous state with different types of orbital correlations and magnetic structure. The key role of intrinsic chemical inhomogeneity in the formation of inhomogeneous magnetic states in solid solutions of manganites is emphasized.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 27-44
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:
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:
Magnetic Behaviour and Electronic Structure of the R$\text{}_{2}$PdSi$\text{}_{3}$ (R = Ce, Nd, Tb-Er) Compounds
Autorzy:
Szytuła, A.
Hofmann, M.
Penc, B.
Ślaski, M.
Majumdar, Subham
Sampathkumaran, E. V.
Zygmunt, A.
Powiązania:
https://bibliotekanauki.pl/articles/2013678.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.-b
75.30.Cr
75.30.Kz
79.60.-i
Opis:
The magnetic properties including the magnetic structure were determined by magnetometric and neutron diffraction measurements of the polycrystalline samples of R$\text{}_{2}$ PdSi$\text{}_{3}$ (R = Ce, Nd, Tb-Er). In Ce$\text{}_{2}$PdSi$\text{}_{3}$ the Ce moments order below 2.5 K. The Nd magnetic moments in Nd$\text{}_{2}$PdSi$\text{}_{3}$ exhibit ferromagnetic ordering below 17 K. In Tb$\text{}_{2}$PdSi$\text{}_{3}$, a complex situation is observed: in the temperature range from 1.5 K to (T$\text{}_{N}$=25 K), there is a coexistence of a ferromagnetic spiral (about 75% of the magnetic moment) and a spin-glass (about 25%). For the Dy, Ho, and Er compounds, below T$\text{}_{N}$ (7.5, 8, and 7 K respectively), sinusoidally modulated structures are observed. The valence band and the core level photoemissions of 4d of rare-earth metal, 3d Pd, 2s and 2p Si were investigated by X-ray photoemission spectroscopy measurements.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 823-826
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of $RSn_{2}$ (R = Tb, Dy) Compounds
Autorzy:
Szytuła, A.
Kaczorowski, D.
Gondek, Ł.
Czub, J.
Nenkov, K.
Powiązania:
https://bibliotekanauki.pl/articles/1538313.pdf
Data publikacji:
2010-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.40.-s
75.30.Kz
72.15.Eb
Opis:
Polycrystalline samples of $TbSn_{2}$ and $DySn_{2}$ were studied by means of magnetic susceptibility, electrical resistivity and heat capacity measurements. Both compounds have been found to order antiferromagnetically at low temperatures with some extra features in the ordered state due to changes in their magnetic structures. The two stannides exhibit metallic conductivity. The estimated crystal field levels splitting of $Tb^{3+}$ and $Dy^{3+}$ ground multiplets do not exceed 75 K.
Źródło:
Acta Physica Polonica A; 2010, 117, 4; 586-589
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of Hexagonal RTIn Rare-Earth Intermetallics with Frustration
Autorzy:
Szytuła, A.
Baran, S.
Gondek, Ł.
Arulraj, A.
Penc, B.
Stüsser, N.
Powiązania:
https://bibliotekanauki.pl/articles/1538314.pdf
Data publikacji:
2010-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Lp
75.30.Kz
Opis:
Magnetic properties, including magnetic structure, of some RTIn compounds (R = Tb-Er; T = Cu, Ni, Pd, Pt, Au) with the hexagonal ZrNiAl-type crystal structure are reported. Distribution of the rare earth atoms in the basal plane is similar to the kagomé-lattice. Magnetic moments are localized exclusively on the rare earth atoms and form different types of magnetic ordering. Experimental results are analyzed within the Ruderman-Kittel-Kasuya-Yosida and crystal electric field frames. Monte Carlo simulations, including the $J_{1}$ and $J_{2}$ exchange integrals between nearest and next nearest spins and Dzialoshinsky-Moriya interaction, were performed resulting in a number of magnetic phases, some of which are in good agreement with the magnetic ordering determined in the neutron diffraction experiments.
Źródło:
Acta Physica Polonica A; 2010, 117, 4; 590-594
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of the RT$\text{}_{2}$X$\text{}_{2}$, RTX$\text{}_{2}$ and RTX Compounds in High Magnetic Fields
Autorzy:
Szytuła, A.
Ivanov, V.
Vinokurova, L.
Powiązania:
https://bibliotekanauki.pl/articles/1929858.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
Opis:
Magnetization curves up to 140 kOe have been measured in the temperature range 4.2-100 K on polycrystalline oriented samples for some RT$\text{}_{2}$X$\text{}_{2}$, RTX$\text{}_{2}$ RTX compounds. The magnetic phase diagrams for all samples are determined.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 293-296
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manganites - Structural Aspects
Autorzy:
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1536851.pdf
Data publikacji:
2010-08
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:
In the work a brief discussion of the structural and magnetic properties of the manganites from the point of view of the micro- and macrostructures is presented. The influence of stoichiometry with the different oxygen parameter δ and doped atoms is discussed. The correlation between the crystal structure parameters and magnetic properties for some manganites is presented.
Źródło:
Acta Physica Polonica A; 2010, 118, 2; 303-306
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:
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
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:
Magnetic Phase Transitions in Pure and Cobalt-Doped Geometrically Frustrated Ni$\text{}_{3}$V$\text{}_{2}$O$\text{}_{8}$ Single Crystals
Autorzy:
Szymczak, H.
Baran, M.
Szymczak, R.
Barilo, S. N.
Bychkov, G. L.
Shiryaev, S. V.
Powiązania:
https://bibliotekanauki.pl/articles/2047217.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Gw
75.30.Kz
75.40.Cx
75.50.-y
Opis:
The results of magnetic measurements performed on geometrically frustrated Ni$\text{}_{3}$V$\text{}_{2}$O$\text{}_{8}$ and Ni$\text{}_{3(1-x)}$Co$\text{}_{3x}$V$\text{}_{2}$O$\text{}_{8}$ single crystals with x=0.03 are presented. It was found that Co doping did not change considerably the magnetic H-T phase diagram. Although no spin-glass effects were observed, nevertheless, a strong effect of 3 at% cobalt doping was evidenced. The main effect of Co-doping concerns the direction of the antiferromagnetic vector, which for Ni$\text{}_{3}$V$\text{}_{2}$O$\text{}_{8}$ appears along the $a$ axis, while for only slightly Co doped crystals - along the $c$ axis. This switching of direction results from distinct changes of the magnetocrystalline anisotropy due to the presence of Co$\text{}^{2+}$ ions strongly coupled to the kagome lattice. The disorder introduced by doping has practically no effect on the magnitude of the isotropic exchange interactions. At the same time the doping suppresses the Dzyaloshinskii-Moriya exchange interactions due to the change of direction of the antiferromagnetic vector.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 71-77
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:
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:
The Effect of Ce Dilution on the Ferromagnetic Ordering in CeAuGe
Autorzy:
Sondezi, B.
Strydom, A.
Powiązania:
https://bibliotekanauki.pl/articles/1384842.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.30.Mb
Opis:
Transport and thermodynamic properties of the well-ordered hexagonal CeAuGe compound have been studied. This compound is known to order ferromagnetically at $T_{C}$ = 10 K with well-defined anomalies in magnetic susceptibility χ(T), electrical resistivity ρ(T) and specific heat $C_p(T)$ characterising the phase transition. The location of $T_{C}$ has been observed to be unstable and enhanced even in moderate applied magnetic fields. However, the dilution of magnetic species, Ce, with the non-f electron element, La, is shown in this work to achieve a continuous suppression of $T_{C}$ to 0 K. The integrity of the space group and the details of the unit cell occupation are retained throughout the substitution series, as is the high-temperature localized Ce-effective magnetic moment $μ_{eff}$ = 2.54 $μ_{B}$/(mol Ce). Our studies of physical properties down to 0.05 K show a quantum critical form of non-Fermi liquid behaviour, characterised by a logarithmic divergence in $C_p(T)$/T data in the very dilute Ce content.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 228-230
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoresistance Anisotropy and Magnetic H-T Phase Diagram of $Tm_{0.996}Yb_{0.004}B_{12}$
Autorzy:
Sluchanko, N.
Azarevich, A.
Bogach, A.
Glushkov, V.
Demishev, S.
Gavrilkin, S.
Gabani, S.
Flachbart, K.
Shitsevalova, N.
Filipov, V.
Vanacken, J.
Moshchalkov, V.
Stankiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/1371466.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Gd
73.43.Qt
75.30.Kz
75.20.Hr
75.50.Ee
Opis:
The antiferromagnetic ground state has been studied by transverse magnetoresistance, heat capacity and magnetization measurements, which were carried out on high quality single crystals of $Tm_{0.996}Yb_{0.004}B_{12}$ dodecaboride in strong magnetic fields at liquid helium temperatures. Both antiferromagnetic-paramagnetic (AF-P) and spin-orientation (AF1-AF2) phase transitions have been observed, and allowed to construct a complicated magnetic H-T phase diagram for this compound. Strong magnetoresistance anisotropy was found both in AF states (ρ(H||[110])/ρ(H||[111])~ 1.2 at H~ 20 kOe) and at the critical field of AF-P transition $(H_{N}[100]$/$H_{N}[111]$~ 1.25) in this magnetic metal with a simple fcc crystal structure.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 332-333
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:
Probing 3d-4f Exchange Interactions by High-Field Magnetization Measurements
Autorzy:
Skourski, Y.
Kuz'min, M.
Skokov, K.
Müller, K.
Wosnitza, J.
Powiązania:
https://bibliotekanauki.pl/articles/1810420.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Et
75.30.Kz
Opis:
In a 4f-3d ferrimagnet the molecular field (a net value expressing the relevant exchange interactions) can be determined from high-field magnetization measurements. If the applied field is high enough, it breaks the ferrimagnetic ground state and drives the system towards ferromagnetic order via non-collinear intermediate phases. Magnetization curves of $Er_2Fe_{17}$ singe crystal were measured along the [100] crystallographic direction in magnetic fields up to 50 T. An unfixed sample, free to rotate, was measured as well. The magnetization measured along the easy magnetization direction shows jumps at 37.5 and 44 T. The first jump was used for the determination of the molecular field (66.4 T). This agrees with the data for the unfixed sample where a kink in the magnetization at 33.5 T yields a molecular field of 65.7 T. The obtained values are in a good agreement with literature data.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 178-180
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport Properties of $CeCo_{12}B_6$ in Vicinity of Phase Transition
Autorzy:
Skorokhod, Y.
Arnold, Z.
Míšek, M.
Kamarád, J.
Isnard, O.
Mayot, H.
Powiązania:
https://bibliotekanauki.pl/articles/1813635.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.-s
72.15.Eb
Opis:
Study of resistivity and specific heat on $CeCo_{12}B_6$ compound was performed in a temperature range 2.5-300 K. The specific heat exhibits pronounced λ-type anomaly in the vicinity of the Curie temperature $T_C$. Using the Debye-Einstein model the following parameters were obtained: the Debye temperature $θ_D$ = 185 K, coefficient of the electron specific heat $γ_{el}$ = 115 mJ/mol K. The parabolic temperature dependence of resistivity ρ(T) = $ρ_0 + A_ρT^2$ was observed below $T_C$ in agreement with ferromagnetic state. Comparison of dρ/dT(T) with $C_M(T)$ allows to confirm their similar character, accordingly to theory of critical behavior.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 259-262
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:
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:
Search for Dimensional Effects in Spin-Glass Transition in Thin Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Multilayers
Autorzy:
Sawicki, M.
Dietl, T.
Skośkiewicz, T.
Karczewski, G.
Wojtowicz, T.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1943818.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Rr
75.50.Lk
75.30.Kz
75.50.-y
Opis:
SQUID magnetic measurements of CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te, x ≃ 0.5, multi-layers with different CdMnTe layer thickness w reveal the persistence of the spin-glass irreversibilities down to ≃ 16 Å thin layers, i.e., well beyond the previously postulated 40 Å as a quasi-2D threshold. The freezing temperature T$\text{}_{f}$ is found to be a monotonic function of w, and it obeys a scaling law T$\text{}_{f}$ ∝ w$\text{}^{a}$, with a 0.8 similar to that for canonical spin-glasses. Magnetic properties of all studied structures are found to be independent of the orientation of the magnetic field.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1038-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mesoscopic Ordering Effects in Single-Crystalline Thin Films of Lanthanum Manganites
Autorzy:
Samoilenko, Z. A.
Okunev, V. D.
Pushenko, E. I.
Abal'oshev, A.
Baran, M.
Gierłowski, P.
Lewandowski, S. J.
Szymczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/2037100.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 thin films of lanthanum manganites epitaxially grown by pulsed laser deposition on single-crystalline substrates. X-ray diffraction studies show that the characteristic feature of the investigated films is a superposition of fractions with long range atomic order in the basic single-crystalline matrix, and mesoscopic order in the clusterized structure encompassing the Mn-O layers. A detailed analysis of diffusive scattering shows that the size of metallic clusters and their volume concentration in the dielectric matrix varies. In the case of a small size and concentration, the metallic clusters in low temperature behave as quantum dots and their presence leads to a tunneling mechanism of conductivity with characteristic R(T)= const. In the case of large cluster size, the discrete energy levels become smeared. It appears also that the optical, transport, and magnetic properties of the investigated films depend critically on the distribution of Mn$\text{}^{2+}$, Mn$\text{}^{3+}$, and Mn$\text{}^{4+}$ ions in the clusters.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 93-98
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure Influence on the Curie Temperature
Autorzy:
Rutkowski, J.
Wojtczak, L.
Zajac, Š.
Powiązania:
https://bibliotekanauki.pl/articles/1506985.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.-s
75.50.Cc
81.40.Vw
64.30.Ef
Opis:
The pressure dependence of the ferromagnetic-paramagnetic phase transition temperature $T_{C}$ (p) is of high interest due to its direct technological implications. The theoretical investigations of the Curie temperature $T_{C}$ (p) considered in the ferromagnetic crystals have been studied employing various methods of calculations. The present paper is devoted to its description by means of the pseudoharmonic approximation approach.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 745-746
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Effects in Spin-Wave Spectrum of the Semi-Infinite FeBr$\text{}_{2}$ Field-Induced Metamagnet
Autorzy:
Rudziński, W.
Maciejewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1930606.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Ds
75.30.Kz
Opis:
Surface spin waves in the layered structure of the FeBr$\text{}_{2}$ field-induced metamagnet are studied theoretically. Surface spin-wave modes are calculated for the (001) surface and for the paramagnetic phase at low temperatures. Allowing the surface exchange parameters to deviate from the bulk values, full richness of the surface spin-wave spectra is displayed. The problem of the stability of the ground state of the system is also discussed.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 433-437
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transitions in Fe-Rh Alloys Induced by Temperature
Autorzy:
Rodionov, V.
Rodionova, V.
Annaorazov, M.
Powiązania:
https://bibliotekanauki.pl/articles/1386516.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.60.Cn
75.30.Kz
64.70.K-
Opis:
This research work was aimed to find the composition of equiatomic Fe-Rh alloy and to find the way of preparation of samples with extremely narrow thermal hysteresis and repeatable results. Alloys with content of Fe from 48 up to 52 at.% were examined. Fe-Rh alloys were prepared in forms of bulk piece, plate and wire. The plates of alloys were found to be more perspective for further investigations. The influence of parameters of ingot and samples treatments on antiferromagnetic-ferromagnetic transition was studied. The ways of narrowing of temperature hysteresis were established.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 445-447
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:
Spin-Glass Transition in the $RCoGaO_{4}$ (R=Lu, Yb) Layered Cobaltites
Autorzy:
Radelytskyi, I.
Szymczak, R.
Dabkowska, H.
Noad, H.
Aleshkevych, P.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/1368512.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Gw
75.30.Kz
75.40.-s
75.50.Lk
Opis:
The frequency, temperature, and the dc and ac dependences of the magnetic susceptibility of the $YbCoGaO_{4}$ and $LuCoGaO_{4}$ single crystals are investigated. The $YbCoGaO_{4}$ behaves like an Ising spin glass with a strong uniaxial anisotropy. In contrast $LuCoGaO_{4}$ is Heisenberg-like spin glass. Dynamical scaling reveals a three dimensional phase transition near Tg and yields critical exponent values between those of Heisenberg- and Ising-like systems.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 230-231
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:
Theoretical Investigation of the Complete Phase Diagram of the SmMn$\text{}_{2}$Ge$\text{}_{2}$ Metamagnet
Autorzy:
Polaszek, P.
Onyszkiewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1929828.pdf
Data publikacji:
1993-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
Opis:
A two-sublattice Ising model with spatial four-spin and six-spin anisotropy added in order to describe SmMn$\text{}_{2}$Ge$\text{}_{2}$ metamagnet is discussed. The complete phase diagrams for this metamagnet as a function of hydrostatic pressure are obtained.
Źródło:
Acta Physica Polonica A; 1993, 84, 6; 1101-1109
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:
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:
Magnetization Processes in Dilute Metamagnets with Ferro- and Antiferromagnetic Exchange Interactions
Autorzy:
Pikuła, R.
Kirkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2046880.pdf
Data publikacji:
2006-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Jk
64.60.Kw
75.10.-b
75.30.Kz
Opis:
Using the Green function method there has been presented the mathematical description of dilute two sub-lattice metamagnets with ferro- and antiferromagnetic exchange interactions. The Green function averaging procedure is based on the Cumulant Expansion Technique and includes any localized Green function irrespectively of the decoupling algorithm making the chain system of equations self-consistent. The derived form of the averaged Green function is the base for the analysis of magnetization processes and phase transitions occurring in the system under the influence of external magnetic field. It has been found in particular that the tricritical point and the second-order phase transition vanish when concentrations of magnetic atoms coupled with different sub-lattice points become different.
Źródło:
Acta Physica Polonica A; 2006, 110, 1; 25-39
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-Step Magnetic Phase Transition in $CeRh_3Si_2$ Studied by Specific Heat Measurements
Autorzy:
Pikul, A.
Kaczorowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/1810486.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Mb
75.50.Ee
75.30.Kz
65.40.Ba
Opis:
High-quality single crystal of a novel cerium silicide $CeRh_3Si_2$, crystallizing with the orthorhombic $ErRh_3Si_2$-type structure, was grown by the Czochralski pulling method and studied by means of specific heat measurements. The antiferromagnetic ordering of the compound manifests itself as a pronounced lambda-shaped anomaly at $T_N$ = 4.72(3) K, and is followed by a spike-shaped anomaly due to spin reorientation at $T_t$ = 4.48(2) K, in good agreement with the previously reported magnetic susceptibility data. Both transitions are very sensitive to applied magnetic field - they split into four separate anomalies, which independently shift to lower temperatures with rising field. Several scenarios are proposed as possible explanations of the multi-step character of the magnetic ordering in $CeRh_3Si_2$.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 235-237
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of the Rapidly Solidified Bulk Alloy: $Fe_{61}Co_{10}B_{20}Y_{8-x}W_{y}Pt_{x}$ (where: x=1,2; y=0,1)
Autorzy:
Pietrusiewicz, P.
Powiązania:
https://bibliotekanauki.pl/articles/1397021.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
75.50.Gg
75.50.Tt
75.30.Kz
75.60.Ej
Opis:
In the literature, research into rapidly cooled Pt-based alloys usually features samples that are produced in the form of thin ribbons. This work presents the effect of the addition of a small quantity of W and Pt on the magnetic properties of massive two-phase alloys, the samples being produced in the form of plates with a thickness of 0.5 mm. Both amorphous and crystalline phases were observed in the alloys, the phase proportions depending on the composition of the alloy. Generally, it is assumed that alloys with added Pt are characterised by a relatively high saturation magnetization and magnetocrystalline anisotropy, which is mainly influenced by the presence of the crystalline phases: FePt and Fe₃Pt. For the investigated alloys, it was noted that the gradual substitution of W and Pt in place of Y within the alloy $Fe₆₁Co₁₀B₂₀Y_{8-x}W_{y}Pt_{x}$ increased the value of saturation magnetization $(μ₀M_{s})$ and reduced the coercive field $(H_{c})$. On the basis of XRD pattern analysis it was found that, within the sample with the highest concentration of Pt, there are crystallites of the smallest size and the proportion of the α-Fe crystalline phase is much greater than for the other studied samples.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 666-668
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:
Reappearance of Antiferromagnetic Order in $Nd_{0.9}Ca_{0.1}BaCo_{2}O_{5+δ}$ for δ > 0.51
Autorzy:
Piętosa, J.
Kolesnik, S.
Puźniak, R.
Dabrowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/1374353.pdf
Data publikacji:
2014-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Gg
62.50.-p
Opis:
The absence of the antiferromagnetic order in $Nd_{0.9}Ca_{0.1}BaCo_2O_{5.5}$ has been found to remain unchanged by applying a hydrostatic pressure of 10 kbar. In magnetic studies of polycrystalline $Nd_{0.9}Ca_{0.1}BaCo_2O_{5+δ}$ (δ=0.07-0.69), we have found a reappearance of the antiferromagnetic phase, caused by an increase in oxygen index δ above 0.51 related to extra oxygen ions addition into the $NdO_{δ}$ plane. For the samples with δ=0.555 and 0.59, a coexistence of well developed antiferromagnetic phase with ferrimagnetic one is evidenced.
Źródło:
Acta Physica Polonica A; 2014, 126, 4a; A-50-A-52
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:
Magnetic Systems at Criticality: Different Signatures of Scaling
Autorzy:
Pełka, R.
Konieczny, P.
Fitta, M.
Czapla, M.
Zieliński, P.
Bałanda, M.
Wasiutyński, T.
Miyazaki, Y.
Inaba, A.
Pinkowicz, D.
Sieklucka, B.
Powiązania:
https://bibliotekanauki.pl/articles/1399023.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.40.-s
75.30.Kz
75.30.Sg
75.50.Xx
Opis:
Different aspects of critical behaviour of magnetic materials are presented and discussed. The scaling ideas are shown to arise in the context of purely magnetic properties as well as in that of thermal properties as demonstrated by magnetocaloric effect or combined scaling of excess entropy and order parameter. Two non-standard approaches to scaling phenomena are described. The presented concepts are exemplified by experimental data gathered on four representatives of molecular magnets.
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 977-989
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:
Micromagnetic Structures near a Second Order Phase Transition in Monocrystalline Ferrite Garnet Plates
Autorzy:
Pamyatnykh, L.
Belskii, I.
Shmatov, G.
Powiązania:
https://bibliotekanauki.pl/articles/1386324.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.60.Ch
75.30.Kz
75.60.Jk
Opis:
The main parameters of micromagnetic structure formation in a vicinity of a second order phase transition were determined experimentally and theoretically. The theoretical study was performed using micromagnetic approach. External magnetic field $H_{c}$ of appearance of micromagnetic structure and micromagnetic structure period $L_{c}$ were determined for (001)-oriented plate with uniaxial $K_{u}$ and cubic K₁ magnetic anisotropy. The plate was saturated by the field applied in its plane. In the model we assumed that magnetization vector undergoes small deviations from equilibrium if magnetic field is slightly reduced. These deviations are periodic in nature: micromagnetic structure has a form of a plane wave. Dependences of $H_{c}$ and $L_{c}$ on an azimuthal angle of external magnetic field and on anisotropy constants $K_{u}$ and K₁ were derived analytically in this work. Experimental studies of micromagnetic structure near the second order phase transition were conducted on (EuEr)₃(FeGa)₅O₁₂ (001)-oriented 50 μm thick ferrite-garnet plate with $K_{u}$ = 5700 erg/cm³ and K₁=-3700 erg/cm³. Micromagnetic structure was revealed by means of magnetooptic Faraday effect. The in-plane field was increased up to 2000 Oe. Experimentally determined values of $H_{c}$ and $L_{c}$ were compared with theoretical estimates.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 421-423
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:
Magnetic Properties of a Novel $CeCo_{0.715}Si_{2.285}$ Compound
Autorzy:
Moudřík, J.
Prokleška, J.
Pospíšil, J.
Sechovský, V.
Císařová, I.
Powiązania:
https://bibliotekanauki.pl/articles/1387062.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.Gw
75.30.Kz
Opis:
We report on the basic physical properties of a novel $CeCo_{0.715}Si_{2.285}$ compound, mainly its rich magnetic phase diagram. The compound crystallizes in the I-4m2 space group structure with extremely elongated unit cell (a = 4.12 Å, c = 32.84 Å). In a zero magnetic field it orders antiferromagnetically at $T_{N}$ = 10.5 K with another order-to-order transition at 9.5 K. Under application of a magnetic field along the c-axis it manifests numerous magnetic transitions in small fields (B < 500 mT), resembling the so-called "devil's staircase" systems. Above 1 T the magnetization is almost constant up to 14 T (maximum magnetic field applied within our study) but considerably reduced (0.3 $μ_B$/Ce) with respect to the free $Ce^{3+}$ ion. After removing the applied field, however, the high field state remains unchanged to be removed in negative fields. The compound also exhibits strong hysteresis of magnetization with respect to varying temperature or magnetic field. For fields applied along the a-axis typical behavior for the hard axis in the material with uniaxial anisotropy is observed.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 561-563
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 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:
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:
Magnetic Field Effect on Yb-Based Heavy Fermions near Magnetic-Nonmagnetic Transition
Autorzy:
Mito, T.
Koyama, T.
Nakagawara, K.
Ishida, T.
Ueda, K.
Kohara, T.
Matsubayashi, K.
Saiga, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1534203.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
75.30.Kz
75.30.Mb
78.70.Dm
Opis:
Recently magnetic field effects on f electron systems in the vicinity of a magnetic-nonmagnetic transition have attracted much interest. In order to investigate the mechanism of field induced modifications in heavy fermion systems, especially in terms of valent degrees of freedom, we have carried out the X-ray absorption spectroscopy measurement on the newly discovered heavy fermion material $YbCo_2Zn_{20}$ which exhibits extremely large specific heat at low temperatures. Our results show that the Yb valence of $YbCo_2Zn_{20}$ is very close to +3 over the whole temperature range of measurement. Besides, no significant change in the absorption spectrum was observed up to the field of 10 T. This contrasts to the previously reported strong field dependence in the resistivity, followed by an expansion of the Fermi liquid regime with increasing field. The obtained results therefore lead to the conclusion that the valent degrees of freedom play a minor role in the strong field dependence of the heavy fermion systems in this compound.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 870-872
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure Effect on Yb-Based Strongly Correlated Electron Systems
Autorzy:
Mito, T.
Otani, M.
Nakamura, M.
Koyama, T.
Wada, S.
Kotegawa, H.
Kobayashi, T.
Idzikowski, B.
Reiffers, M.
Sarrao, J.
Powiązania:
https://bibliotekanauki.pl/articles/1810284.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
75.30.Kz
75.30.Mb
76.60.-k
Opis:
We studied pressure effects on $YbCu_5$ and $YbInCu_4$, good examples of the Yb-based compounds to investigate the nonmagnetic-magnetic transition in Yb-based strongly correlated electron systems. With increasing pressure, the low-temperature Fermi liquid state of $YbCu_5$ is gradually suppressed, suggesting the second-order like nonmagnetic-magnetic transition around the pressure of 5-6 GPa. On the other hand, in $YbInCu_4$ which has a pressure-induced magnetic ordered ground state above $P_C$=2.45 GPa, both high-temperature paramagnetic and low-temperature intermediate valence phases are insensitive to pressure. Our results confirm the first-order nature of the transition between the intermediate valence and magnetic ordered phases with pressure.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 47-52
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Transport Properties of $CeCo_{12}B_6$ and $CeFe_2Co_{10}B_6$ Compounds under Pressure
Autorzy:
Míšek, M.
Arnold, Z.
Skorokhod, Y.
Kamarád, J.
Isnard, O.
Mayot, H.
Powiązania:
https://bibliotekanauki.pl/articles/1813638.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.-b
75.25.+z
75.30.Kz
Opis:
Study of pressure effects on magnetic and transport properties of $CeCo_{12}B_6$ and $CeFe_2Co_{10}B_6$ was performed in temperature range 5-300 K at pressures up to 9 kbar. The significant decrease in the Curie temperature $T_C$ as a consequence of Fe substitution from (135±1) K to (85±1) K is not accompanied by the changes of saturation magnetization. The decrease in $T_C$ with pressure is the same for both samples -Δ$T_C$/Δp ≈ -0.5 K/kbar. The relative decrease in saturation magnetization with pressure is about 0.3%/kbar for both samples. Pressure induced resistivity changes were below 1%. The relatively low pressure effect on both the $T_C$ and magnetization can be attributed to the hybridization as a consequence of small distances between the Co and B atoms.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 263-266
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:
Magnetic Properties of $La_{0.8}K_{0.2}MnO_{3}$ Nanoparticles
Autorzy:
Mihalik, M.
Zentková, M.
Briančin, J.
Fitta, M.
Lazúrová, J.
Vavra, M.
Powiązania:
https://bibliotekanauki.pl/articles/1371270.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.-y
75.47.Lx
75.30.-m
75.30.Kz
Opis:
Magnetic properties of $La_{0.8}K_{0.2}MnO_{3}$ have been studied on nanoparticles prepared by glycine-nitrate method. Crystal structure and particles size were modified by heat treatment. Crystal structure changes from orthorhombic (space group Pbma) to rhombohedral (space group R-3c) after annealing at 600°C/2 hours. The average size of particle varies with annealing from about 30 nm to 135 nm. The Curie temperature $T_{C}$ and the saturated magnetization $μ_{s}$ increase with annealing. The exchange bias effect was observed on samples with particles size smaller than 60 nm.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 312-313
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:
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:
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:
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:
On the Critical Behaviour and Phase Diagram of Ising-like Metamagnet in a Transverse Field
Autorzy:
Lukierska-Walasek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1930584.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
81.30.Dz
05.70.Fh
Opis:
The quantum Ising-like metamagnet in a field Γ perpendicular to the easy direction in the mean field approximation is investigated. The conditions for the existence of critical and tricritical points have been analyzed. The result is illustrated by an appropriate plot in three-dimensional space of the following parameters: the temperature, Γ, and field parallel to the easy direction.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 381-384
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Approach to the Phenomenology of Amorphous Curie-Point Relaxation
Autorzy:
Lovas, A.
Powiązania:
https://bibliotekanauki.pl/articles/1507126.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Kj
75.30.Kz
Opis:
The possible origin of short range atomic displacements coupled with the irreversible amorphous Curie temperature relaxation (Δ $T_{C}^{am}$) in Fe-based glasses is discussed and analyzed on the basis of quenched-in phase reminiscences. The displacements are dominantly symmetry changes, which are governed by the relative stability of fcc and bcc quenched-in phase reminiscences at a given temperature range. Those of elements which cause positive Δ $T_{C}^{am}$ in as quenched state, also cause positive irreversible Δ $T_{C}^{am}$ during structural relaxation. The influence of Cr addition is just the opposite in this respect.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 770-772
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metastable Magnetic Structures in the Blume-Capel Model
Autorzy:
Kułakowski, K.
Antoniuk, M.
Del Moral, A.
Gawroński, P.
Powiązania:
https://bibliotekanauki.pl/articles/2013716.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Fh
75.10.Hk
75.30.Kz
Opis:
We discuss a first-order phase transition from non-magnetic to magnetic phase at T=0. New results are presented on a spontaneously formed magnetic phase and its energy in the C15 atomic structure, in the presence of the antiferromagnetic interaction. A dynamic phase diagram is constructed for the phase transition. The results are discussed in the context of the pressure-driven phase transition, which was observed experimentally in YMn$\text{}_{2}$.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 893-896
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-Collinear Magnetism in Itinerant-Electron Systems
Autorzy:
Kübler, J.
Powiązania:
https://bibliotekanauki.pl/articles/2012876.pdf
Data publikacji:
2000-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Mb
75.10.Lp
75.30.Ds
75.30.Kz
Opis:
The Heisenberg model cannot uncritically be applied to itinerant-electron magnets, including those that show non-collinear order. Density functional theory is therefore generalized to apply to non-collinear itinerant-electron magnets. The appropriate Kohn-Sham equations are discussed and the total energy of spiral magnetic order is used to determine the magnon spectrum in the adiabatic approximation. The energy spectrum of transverse spin fluctuations can also be estimated with the total energy of spiral magnetic order and allows a determination of thermal properties of itinerant-electron magnets. Calculated results for Fe, Co, Ni, and FeCo are discussed and compared with experimental results.
Źródło:
Acta Physica Polonica A; 2000, 97, 1; 165-173
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:
Magnetic Coupling in CuCr$\text{}_{2}$X$\text{}_{4}$ (X = S, Se) Spinel Compounds Obtained via Substitution of the Chromium Ions by Nonmagnetic Sb or Al Ions
Autorzy:
Krok-Kowalski, J.
Malicka, E.
Władarz, G.
Groń, T.
Pawełczyk, M.
Heimann, J.
Pacyna, A. W.
Powiązania:
https://bibliotekanauki.pl/articles/2048127.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
Taking into account both the dc magnetic susceptibility and the magnetization measurements as well as the high-temperature expansion of the magnetic susceptibility procedure the hopping integrals and superexchange integrals for the first and second coordination sphere were evaluated. The two hopping integrals are positive and many times greater than the superexchange ones. The obtained results testify to that in the stoichiometric compounds under study the double-exchange magnetic interaction is the main mechanism responsible for very strong, ferromagnetic coupling. Using the total hopping integral B the bandwidth of mixed valence band of chromium ions was determined.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 705-707
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Magnetic Studies of the Fe-Co-Zr-Mo-W-B Amorphous Alloy
Autorzy:
Kotynia, K.
Pawlik, P.
Hasiak, M.
Pruba, M.
Pawlik, K.
Powiązania:
https://bibliotekanauki.pl/articles/1030235.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
75.50.Kj
75.30.Sg
75.30.Kz
75.40.-s
Opis:
The paper presents a characterization of the phase structure by X-ray diffraction and isothermal magnetic entropy changes for the amorphous Fe₅₈Co₁₀Zr₁₀Mo₅W₂B₁₅ alloy sample in the as-quenched state. An ingot sample was obtained by arc-melting. The ribbon sample was obtained by the melt-spinning technique. The magnetic measurements at various temperatures allowed for the study of the Curie temperature T_{C} and magnetic entropy changes |ΔS_{M}|. In order to determine the Curie temperature T_{C} of amorphous phase, three independent methods were used. Determination of the Curie temperature T_{C} for the amorphous alloys is not a trivial problem, as magnetization does not decreases rapidly around T_{C}. Therefore it is essential issue to establish T_{C} using few complementary methods. X-ray diffraction analysis revealed a fully amorphous structure of the ribbon samples.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1204-1206
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Diagrams of the Spin-1/2 Ising-Heisenberg Model on a Triangle-Hexagon Lattice
Autorzy:
Kiššová, J.
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1506906.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.30.Rt
05.50.+q
05.70.Jk
75.10.Kt
75.10.Jm
75.30.Kz
Opis:
Ground-state and finite-temperature phase diagrams of a geometrically frustrated spin-1/2 Ising-Heisenberg model on a triangle-hexagon lattice are investigated within the generalized star-triangle mapping transformation. It is shown that the ground state is constituted by two different spontaneously long-range ordered phases and one disordered spin-liquid phase.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 730-731
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Model for Ferromagnetic Thin Films with an Alternating Crystal Field
Autorzy:
Kecer, J.
Tuleja, S.
Powiązania:
https://bibliotekanauki.pl/articles/1813606.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Ds
75.30.Kz
75.70.Ak
Opis:
Within the framework of many-body Green's function theory there are studied the properties of the quantum Blume-Capel model for ferromagnetic films with an alternating single-ion anisotropy on the odd atomic layers and on the even ones. We analyse various possible phase diagrams for the surface exchange couplings and the single-ion anisotropy parameters.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 197-200
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:
Magnetocaloric Effect in Materials with the First Order Transitions - Direct Measurements
Autorzy:
Kamarád, J.
Kaštil, J.
Arnold, Z.
Javorský, P.
Sechovský, V.
Powiązania:
https://bibliotekanauki.pl/articles/1535138.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
75.50.Cc
Opis:
The results of direct measurements of the magneto-caloric characteristics Δ $T_{ad}$ and the indirect determination of Δ $S_{m}$ of pure Gd around the Curie temperature and of the $FeMnP_{0.45}As_{0.55}$ and $Ni_{45}Co_5Mn_{31}Ga_{19}$ intermetallics in the vicinity of the first order magnetic and structural phase transitions are presented and discussed. A pronounced temperature and field dependence of the first order transitions in the studied materials manifests restrictions applying these materials in magnetic refrigeration techniques. An effective use of the Ericsson and the Brayton refrigeration cycles with $FeMnP_{0.45}As_{0.55}$ in the role of a refrigerant is discussed.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 1000-1001
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoelastic Anomalies and Suppression of Jahn-Teller Distortions in La$\text{}_{1-x}$Sr$\text{}_{x}$MnO$\text{}_{3}$ by Pulsed Magnetic Fields
Autorzy:
Kadomtseva, A. M.
Popov, Yu. F.
Vorob'ev, G. P.
Kamilov, K. I.
Ivanov, V. Yu.
Mukhin, A. A.
Balbashov, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/2013240.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Pp
Opis:
Thermal expansion Δl/l(T) and magnetostriction λ$\text{}_{∥, ⊥ }$(H,T) in the pulsed magnetic fields H up to 250 kOe were studied in the single La$\text{}_{1-x}$Sr$\text{}_{x}$MnO$\text{}_{3}$ crystals (x=0.1, 0 .125, and 0.15) at temperatures T=10-320 K. Anomalies in the Δl/l (T) curves were observed near a charge (polaron) ordering (T$\text{}_{p}$) and structural transitions between orthorhombic Jahn-Teller distorted O' phase and high temperature orthorhombic (pseudocubic) O$\text{}^{*}$ one (T'$\text{}_{s}$). A noticeable increase in the field-induced magnetostriction λ$\text{}_{∥, ⊥ }$(H) was revealed in the O' phase at T$\text{}_{p}$
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 599-602
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Related Properties of Ternary TmTX Intermetallics
Autorzy:
Kaczorowski, D.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1387896.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.Cr
75.30.Kz
75.50.Ee
75.47.Np
75.40.Cx
Opis:
We report on the magnetic and thermal properties of a few TmTX compounds, where T = d-electron metal and X = p-electron element. In all these ternaries but TmRuGe the thulium magnetic moments order antiferro- or ferromagnetically at low temperatures. The specific heat data confirms the magnetic orderings and reveals the influence of crystalline electric field effects.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 620-622
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Diagram of $TmB_4$ Probed by AC Calorimetry
Autorzy:
Kačmarčík, J.
Pribulová, Z.
Gabáni, S.
Samuely, P.
Siemensmeyer, K.
Shitsevalova, N.
Flachbart, K.
Powiązania:
https://bibliotekanauki.pl/articles/1534368.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Ee
Opis:
TmB_4 is a frustrated system based on the Shastry-Sutherland lattice that exhibits complex magnetic properties. In this contribution the magnetic field B vs. temperature T phase diagram of $TmB_4$ has been studied by ultrasensitive AC calorimetry in the temperature range between 2.9 and 12 K and in magnetic fields up to 8 T. Apart from already known phases our measurements have recognized several new phase transitions suggesting that the phase diagram of $TmB_4$ is even more complex and deserves further studies.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 903-904
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Mössbauer Study of Cerium-Based Reactive Sorbent
Autorzy:
Jiraskova, Y.
Bursik, J.
Zivotsky, O.
Lunacek, J.
Janos, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032876.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Tt
75.60.Ej
76.80.+y
61.46.Df
75.30.Kz
75.50.Bb
Opis:
A new kind of magnetically separable composite consisting initially of magnetite and cerium carbonate nanograins was investigated using magnetic and Mössbauer methods at room and low temperatures. Various stages of calcination treatment in air resulted in a transformation of the cerium carbonate into cerium dioxide and magnetite into more complicated iron oxide compositions. The final CeO₂ nanograins on the surface of α-Fe₂O₃ were obtained after calcination at 973 K.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 1096-1098
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:
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:
On Non-Ising Phase Transitions in the 3D Standard Ashkin-Teller Model
Autorzy:
Jeziorek-Knioła, D.
Musiał, G.
Dębski, L.
Rogiers, J.
Dylak, S.
Powiązania:
https://bibliotekanauki.pl/articles/1427129.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Hk
75.30.Kz
75.40.Cx
75.40.Mg
Opis:
The phase transition line near the Ising point region is studied for the 3D standard Ashkin-Teller model on a cubic lattice. This model with a multicomponent order parameter is one of the important reference points in statistical physics since it shows an interesting and complicated phase diagram. The main motivation for our study was nonuniversal behavior suggested for this line. The large-scale Monte Carlo simulations using the Binder and Challa like cumulants are performed. Accurate analysis to exclude the latent heat inherence is applied. Specific behavior of the Challa like cumulants is discovered and its interpretation is proposed. The paper is closed with preliminary conclusions concerning the continuous but non-Ising character of these phase transitions in the lower part of the mixed phase region and the possiblity of the first order on the line connecting it to the Ising point.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1105-1107
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:
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:
Magnetic Properties of NdCo$\text{}_{2}$Si$\text{}_{2}$, TbCo$\text{}_{2}$Si$\text{}_{2}$ and DyCo$\text{}_{2}$Si$\text{}_{2}$ in High Magnetic Fields
Autorzy:
Ivanov, V.
Vinokurova, L.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1920794.pdf
Data publikacji:
1992-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
Opis:
The magnetic properties of RCo$\text{}_{2}$Si$\text{}_{2}$ (R = Nd, Tb, Dy) compounds were studied by measuring the high-field magnetization in magnetic fields up to 140 kOe and over the temperature range 4.2-45 K. The magnetic field induces in NdCo$\text{}_{2}$Si$\text{}_{2}$ three metamagnetic phase transitions and two transitions in TbCo$\text{}_{2}$Si$\text{}_{2}$ and DyCo$\text{}_{2}$Si$\text{}_{2}$ compounds.
Źródło:
Acta Physica Polonica A; 1992, 81, 6; 693-698
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parallel Susceptibility of Thin Ferromagnetic Films within Many-Body Greens Function Theory
Autorzy:
Ilkovič, V.
Kecer, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813608.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Ds
75.30.Kz
75.70.Ak
Opis:
Parallel susceptibility of the quantum Blume-Capel model for ferromagnetic films is calculated within the Green function theory. The Hamiltonian includes a Heisenberg term with the different surface exchange coupling with respect to bulk, an external magnetic field, a second-order uniaxial single-ion anisotropy, and the exchange anisotropy. The importance of collective excitations is demonstrated by comparing with result calculated within mean field approximation.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 201-204
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatially Anisotropic Spin J₁-J₂ Heisenberg Model for an Antiferromagnetic Square Lattice: Phase Diagrams
Autorzy:
Ilkovič, V.
Powiązania:
https://bibliotekanauki.pl/articles/1030571.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Ds
75.30.Kz
75.70.Ak
Opis:
The new magnetic materials such as the layered oxide high-temperature superconductor can be well described by the Heisenberg spin model with nearest-neighbor coupling J₁ and next-nearest-neighbor coupling J₂. A generalization of the J₁-J₂ model is the J₁^{x}-J₁^{y}-J₂ model where the nearest-neighbor bonds have different strengths J₁^{x} and J₁^{y} in the x and y directions, respectively. The effect of the couplings J₂ and J₁^{y} on the antiferromagnetic Néel state is investigated within the quantum many-body Green function method.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 206-209
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Magnetic Reorientation in Ferrimagnetic Systems
Autorzy:
Ilkovič, V.
Powiązania:
https://bibliotekanauki.pl/articles/1199530.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Ds
75.30.Kz
75.70.Ak
Opis:
The Green function theory is used to study the phenomenon of magnetic reorientation in the ferrimagnetic system. The two-sublattice ferrimagnetic system, with different spins and the intra-sublattice ferromagnetic exchange interactions, is considered. The magnon fluctuations supress in different way the magnetic orders of the sublattices and one obtains two magnetic orders. Each of these orders has different reorientation temperatures.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 34-35
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Reorientation Temperature in an Antiferromagnetic Monolayer
Autorzy:
Ilkovič, V.
Kecer, J.
Powiązania:
https://bibliotekanauki.pl/articles/1534181.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Ds
75.30.Kz
75.70.Ak
Opis:
The reorientation temperature in an antiferromagnetic square lattice is studied within the framework of many-body Green function theory. The model Hamiltonian includes a Heisenberg term, second-order single-ion anisotropy, and a transverse external magnetic field in the x-direction. We investigate the orientation temperature as a function of the single-ion anisotropy parameter and for different transverse magnetic fields.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 854-855
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Structural Study of $Mn_{1.15}Fe_{0.85}P_{1-x}Ge_{x}$ (0.25 < x < 0.32) Magnetocaloric Compounds Prepared by Arc Melting
Autorzy:
Hawelek, L.
Wlodarczyk, P.
Zackiewicz, P.
Polak, M.
Kaminska, M.
Puźniak, R.
Radelytskyi, I.
Kolano-Burian, A.
Powiązania:
https://bibliotekanauki.pl/articles/1402326.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
61.05.C-
61.66.Fn
Opis:
Recently, room temperature magnetocaloric materials increasingly attracted attention in the development of magnetic refrigerators. In this paper, an effect of P/Ge substitution on the magnetic phase transition in the series of $Mn_{1.15}Fe_{0.85}P_{1-x}Ge_{x}$ (0.25 < x < 0.32) magnetocaloric compounds prepared by the arc melting technique and subsequent homogenization process has been studied. Calorimetric and magnetization results show that the temperature of structural phase transition coincide with the Curie temperature and fall within the temperature range 270-355 K. The magnetic entropy change reaches the maximum value for the compound with x=0.28 and equals to 32 J/(kg K) for the magnetic field change of 5 T. The adiabatic temperature change for the same sample, measured using magnetocalorimeter, is equal to 1.2 K for the magnetic field change of 1.7 T. It was found that the increase of Ge content in the sample causes weakening of first order magnetic transition, which is manifested by the lowering difference in transition temperature measured in two zero-field-cooling and field-cooled-cooling regimes.
Źródło:
Acta Physica Polonica A; 2015, 128, 1; 76-80
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:
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:
Magnetic Properties of $URu_{1-x}Pd_{x}Ge$ Solid Solutions
Autorzy:
Gralak, D.
Zaleski, A.
Tran, V.
Powiązania:
https://bibliotekanauki.pl/articles/1371286.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.30.-m
75.50.-y
Opis:
The magnetic properties of the solid solutions $URu_{1-x}Pd_{x}Ge$ with x = 0.1 - 0.9, crystallizing in the orthorhombic TiNiSi-type structure, were investigated by ac magnetic susceptibility and dc magnetization measurements. The experimental data reveal that there are three different regions of magnetic behaviour. A nonmagnetic ground state occurs for x < 0.3, however, as the Pd concentration is increased, the antiferromagnetism is stabilized for x=0.35 - 0.8, and two successive transitions, antiferro- and ferromagnetic, emerge in the x=0.9 composition.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 314-315
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic properties and flux distribution in the LaFeCoSi/FeCoV hybrid structure
Autorzy:
Gozdur, R.
Lebioda, M.
Najgebauer, M.
Powiązania:
https://bibliotekanauki.pl/articles/1055094.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
75.50.Bb
Opis:
The study contains a description of magnetic properties of LaFeCoSi/FeCoV structure. The hybrid structure contains magnetocaloric LaFeCoSi core with high-induction ferromagnetic laminations. The magnetic field inside the magnetic structure is gained by the fringe field from FeCoV laminations. Results of modelling and experimental investigations of modified magnetic properties of LaFeCoSi/FeCoV structure were presented and discussed in the paper.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1294-1297
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power Losses in $LaFe_{x}Co_{y}Si_{1.1}$ Intermetallics near the Magnetic Phase Transition
Autorzy:
Gozdur, R.
Lebioda, M.
Bernacki, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/1402334.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
75.50.Bb
Opis:
The paper presents magnetic parameters of $LaFe_{x}Co_{y}Si_{1.1}$ bulk specimens proving strong magnetocaloric effect. The main research work was oriented on measurements of the alloy's power losses according to IEC 60404 standards and validated with unbalanced bridge method and other methods. The measurements of the $LaFe_{10.8}Co_{1.1}Si_{1.1}$ specimens were determined in the range of temperatures near the Curie temperature where the magnetocaloric effect is the strongest. Power losses were taken into account mainly for the evaluation of usefulness and efficiency in the magnetic refrigeration applications. The results of presented measurements testify that the most suitable range of temperature and the best operational conditions are very close to the point of magnetic phase transition and slightly above it. It indicates that the magnetic state between the $T_{ \Delta S max}$ and $T_{c}$ is more effective for the magnetic refrigeration applications due to lower power losses and high level of the isothermal changes of entropy. Operating temperature below the $T_{ \Delta S max}$ in ferromagnetic state is improper because of the increasing power losses which achieve the level of 130 mJ/kg for main frequency and decrease to 20 mJ/kg for the value of 0.1 Hz.
Źródło:
Acta Physica Polonica A; 2015, 128, 1; 98-103
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-100 z 142

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