Informacja

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

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

Wyszukujesz frazę "75.30.Kz" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-100 z 142
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:
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:
The Distribution of Magnetization for a Stepped Ferro-Antiferromagnet Interface
Autorzy:
Dudko, O. K.
Kovalev, A. S.
Powiązania:
https://bibliotekanauki.pl/articles/2013075.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
Opis:
Magnetization distribution of a disclination type connected with the atomic step on the ferro-antiferromagnet boundary is studied. The results are generalized for the periodic stepped interface.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 479-482
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:
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:
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:
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:
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 and Magnetocaloric Effect οf $R_{1-x}R_{x}Mn_{2}Ge_{2}$ Compounds
Autorzy:
Duraj, M.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1538438.pdf
Data publikacji:
2010-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.30.Sg
Opis:
The magnetic and magnetocaloric properties of $Sm_{1-x}Gd_{x}Mn_{2}Ge_{2}$ compounds with 0 ≤ x ≤ 0.10 have been studied. $SmMn_{2}Ge_{2}$ is antiferromagnetic below the Néel temperature $T_{N}$ ( ≈ 400 K). Further cooling leeds to canted ferromagnetic phase below $T_C$ = 341 K. With decreasing temperature, two metamagnetic phase transitions are observed: F2-AF1 at $T_2$ = 153 K and AF1-F1 at $T_1$ = 106 K. The maximum values of magnetic entropy change | Δ $S_m$ | are found to be 1.5 J $K^{-1} kg^{-1}$ at $T_{1}$ and 2.0 J $K^{-1} kg^{-1}$ at $T_{2}$ in $SmMn_{2}Ge_{2}$. The MCE is found to increase with Gd concentration, | Δ $S_{m}(T_{1})$ | = 3.3 J $K^{-1} kg^{-1}$, while | Δ $S_{m}(T_{2})$ | is slightly enhanced for x = 0.1. The magnetocaloric effect is found to be positive at $T_{1}$ and negative at $T_{2}$.
Źródło:
Acta Physica Polonica A; 2010, 117, 4; 603-606
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:
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:
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:
Phase Transitions in Magnetic and Superconducting Systems with Fluctuating Valence. Chemical Potential Evidence
Autorzy:
Gosławska, E.
Matlak, M.
Eid, Kh.
Powiązania:
https://bibliotekanauki.pl/articles/2013336.pdf
Data publikacji:
2000-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.Cx
Opis:
We investigate the critical behaviour of the chemical potential and average occupation numbers using the extended s -f model with intersite Cooper pairing for systems with fluctuating valence. The model is able to describe phase transitions from normal ferromagnet to normal paramagnet at $T=T_{C}$, from superconducting paramagnet to normal paramagnet at $T=T_{S}$, as well as reentrant phase transitions with three critical temperatures $T_{S_{1}}, T_{C}$ and $T_{S_{2}} (T_{S_{1}} < T_{C} < T_{S_{2}})$. Present investigation, as well as recent results obtained for another models suggest one-to-one correspondence between critical temperatures of the system and kinks appearing in the temperature dependence of the chemical potential and average occupation numbers. This, in turn, indicates a possibility to apply the measurement of the chemical potential vs. temperature as an experimental universal tool when looking for phase transitions in solids.
Źródło:
Acta Physica Polonica A; 2000, 97, 4; 713-718
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manifestation of Spin-Glass-Like Behavior in the Organometallic Magnet
Autorzy:
Dyakonov, V. P.
Arciszewska, M.
Dobrowolski, W.
Szewczyk, A.
Szymczak, H.
Aksymentieva, E.
Varyukhin, V.
Zubov, E.
Gutowska, M. U.
Powiązania:
https://bibliotekanauki.pl/articles/2013705.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.Cx
Opis:
Ac susceptibility (χ$\text{}_{ac}$) and dc magnetization (M$\text{}_{dc}$) of the organometallic magnet Na[FeO$\text{}_{6}$(C$\text{}_{10}$H$\text{}_{8}$N)$\text{}_{3}$] have been studied in temperature range of 4.2-200 K, in an external magnetic field up to 16 kOe. Some peculiarities of the χ$\text{}_{ac}$ and M $\text{}_{dc}$ behavior, which are characteristic of spin-glasses, e.g. cusps in the susceptibility and zero-field-cooled magnetization, an irreversibility between the field-cooled and zero-field-cooled magnetization and dependences of the T$\text{}_{cusp}$ temperature on the frequency and the intensity of the magnetic field, were observed at low temperatures.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 863-866
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:
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:
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:
Magnetic Structure and Phase Diagram of $TmB_4$
Autorzy:
Gabáni, S.
Maťaš, S.
Priputen, P.
Flachbart, K.
Siemensmeyer, K.
Wulf, E.
Evdokimova, A.
Shitsevalova, N.
Powiązania:
https://bibliotekanauki.pl/articles/1813619.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.25.+z
Opis:
Magnetic structure of single crystalline $TmB_4$ has been studied by magnetization, magnetoresistivity, and specific heat measurements. A complex phase diagram with different antiferromagnetic phases was observed below $T_{N1}$=11.7 K. Besides the plateau at half-saturated magnetization (1/2 $M_S$), also plateaus at 1/9, 1/8 and 1/7 of $M_S$ were observed as a function of applied magnetic field Bparallel c. From additional neutron scattering experiments on $TmB_4$, we suppose that these plateaus arise from a stripe structure which appears to be coherent domain boundaries between antiferromagnetic-ordered blocks of 7 or 9 lattice constants. The received results suggest that the frustration among the $Tm^{3+}$ magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland lattice, leads to a strong competition between antiferromagnetic and ferromagnetic order. Thus, stripe structures in intermediate field appear to be the best way to minimize the magnetostatic energy against other magnetic interactions among the Tm ions combined with very strong Ising anisotropy.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 227-230
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:
Theoretical Study of Phase Diagrams for Reentrant Superconducting Er$\text{}_{1-x}$Ho$\text{}_{x}$X, Er$\text{}_{1-x}$Gd$\text{}_{x}$X, Er$\text{}_{1-x}$Tm$\text{}_{x}$X, Ho$\text{}_{x}$Lu$\text{}_{1-x}$X, and Sm$\text{}_{1-x}$Er$\text{}_{x}$X (X = Rh$\text{}_{4}$B$\text{}_{4}$) Alloys
Autorzy:
Gosławska, E.
Matlak, M.
Powiązania:
https://bibliotekanauki.pl/articles/2013024.pdf
Data publikacji:
2000-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.Cx
Opis:
We consider a simplified version of the s-f model, supplemented by the intersite Cooper pairs interaction between conduction electrons with opposite spins to investigate ferromagnetic and superconducting properties of an alloy Re$\text{}_{1-x}^{(1)}$Re$\text{}_{x}^{(2)}$X (Re$\text{}^{(1),(2)}$ - rare earth elements, X = Rh$\text{}_{4}$B$\text{}_{4}$) using the virtual crystal approximation. For a suitable choice of the model parameters we can reproduce the phase boundaries of the experimentally measured phase diagrams for Er$\text{}_{1-x}$Ho$\text{}_{x}$X, Er$\text{}_{1-x}$Gd$\text{}_{x}$ X, Er$\text{}_{1-x}$Tm$\text{}_{x}$X, Ho$\text{}_{x}$Lu$\text{}_{1-x}$X, and Sm$\text{}_{1-x}$Er$\text{}_{x}$X alloys.
Źródło:
Acta Physica Polonica A; 2000, 97, 3; 415-418
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:
Magnetocaloric Effect and Transition Order in $HoAl_{2}$
Autorzy:
Baran, S.
Duraj, R.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1399261.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.30.Sg
Opis:
Magnetic measurements of $HoAl_{2}$ are reported. The compound crystallizes in the cubic $MgCu_{2}$-type crystal structure. $HoAl_{2}$ exhibits two successive magnetic transitions: below $T_{c}$ = 29 K a ferromagnetic order is formed while anomaly at $T_{t}$ = 20 K is related to reorientation of magnetic moment. Near transition temperatures a magnetocaloric effect with magnetic entropy changes -$ΔS_{m}$ equal to 6.3 J/(mol K) at $T_{c}$ and 5.0 J/(mol K) at $T_{t}$ for an external field $μ_{0}H$ = 9 T is observed.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 815-817
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:
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:
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 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:
Magnetic and Thermodynamic Properties of Ce₄RuAl
Autorzy:
Debnath, J.
Strydom, A.
Sondezi, B.
Tappe, F.
Pöttgen, R.
Powiązania:
https://bibliotekanauki.pl/articles/1384856.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.30.Mb
Opis:
The results of magnetic susceptibility and heat capacity measurements are reported for the Ce₄RuAl compound above room temperature to low temperature range (400 K to 0.34 K) and in the magnetic field up to 7 T. The magnetic susceptibility χ(T) exhibits a distinct anomaly at 0.95 K which most probably suggests a paramagnetic to antiferromagnetic phase transition. The magnetic susceptibility obeys the Curie-Weiss law in the region 100-400 K and revealed an effective magnetic moment $μ_{eff}$=2.18 $μ_{B}$/Ce which is less than the value for free Ce³⁺ ($μ_{eff}$=2.54 $μ_{B}$). The paramagnetic Weiss temperature indicates net antiferromagnetic correlations. In the specific heat a peak at 1.3 K supports the bulk nature of the phase transition observed in χ(T). The Sommerfield coefficient is moderately enhanced in the paramagnetic phase, and suggests f-c correlations among the electrons prior to magnetic ordering. The obtained Sommerfield coefficient γ behavior is consistent with the Anderson model-based theoretical predictions.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 237-239
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weak Ferromagnetism in the Helimagnet $Ba_{2}CuGe_{2}O_{7}$
Autorzy:
Chovan, J.
Marder, M.
Papanicolaou, N.
Powiązania:
https://bibliotekanauki.pl/articles/1366485.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Ds
75.30.Gw
75.30.Kz
Opis:
The Dzyaloshinskii-Moriya anisotropy, responsible for helimagnetism in $Ba_{2}CuGe_{2}O_{7}$, has recently been shown to comprise also a weak-ferromagnetic component. We theoretically demonstrate the signatures of weak-ferromagnetism in the magnon spectrum when a magnetic field is applied perpendicular to the z axis. We also anticipate the occurrence of unconventional domain walls in the so-called intermediate phase, and briefly elucidate the importance of the weak ferromagnetic component of the Dzyaloshinskii-Moriya anisotropy for the dynamics of driven domain walls.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 32-33
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:
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:
Influence of Co Doping on Crystal and Magnetic Properties of $Gd_2Cu_2In$
Autorzy:
Gondek, Ł.
Szytuła, A.
Kaczorowski, D.
Szewczyk, A.
Gutowska, M.
Tyvanchuk, Yu.
Kalychak, Ya.
Powiązania:
https://bibliotekanauki.pl/articles/1419907.pdf
Data publikacji:
2012-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.Kz
75.50.Ee
Opis:
Physical properties of $Gd_2Cu_{2 - x}Co_{x}In$ (x = 0.1, 0.2, 0.3) samples are investigated. The paper brings results of X-ray diffraction, magnetometric as well as specific heat studies. It was found that only sample with x = 0.1 exhibits desired crystal structure. Other compositions show existence of impurities due to lack of dissolution Co atoms. For $Gd_2Cu_{1.9}Co_{0.1}In$ sample the Curie temperature of 92.5 K was evidenced. Thus, an enhancement of ferromagnetic correlations with comparison to $Gd_2Cu_2In$ sample was evidenced. It was found that $Gd_2Cu_{1.9}Co_{0.1}In$ sample exhibits magnetocaloric effect within broad temperature range.
Źródło:
Acta Physica Polonica A; 2012, 122, 1; 216-219
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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
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:
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:
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 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:
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:
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:
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:
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:
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:
Influence of Cu, Ga and Au Dopants and Technology Conditions on the Magnetic Interactions in $HgCr_2Se_4$ Single Crystals
Autorzy:
Krok-Kowalski, J.
Władarz, G.
Groń, T.
Duda, H.
Pacyna, A.
Nikiforov, K.
Rduch, P.
Powiązania:
https://bibliotekanauki.pl/articles/1493008.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
For single crystals $HgCr_2Se_4$ doped by nonmagnetic $Cu^{+},$ $Au^{2+}$ and $Ga^{3+}$ ions and single crystals of $HgCr_2Se_4$ matrix growing in different synthesis conditions both the dc and ac magnetic susceptibility as well as the magnetization have been measured. As it follows from the analysis of the obtained results, paradoxically, the dopants strengthen the long range magnetic interactions of the ferromagnetically ordered single crystals under study, evidenced by the higher values of the ordering temperature in comparison with those ones for pure matrix. An influence of the technological processes connected with deficiency and/or excess of Hg on the long range magnetic interactions was not observed.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 970-972
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Temperature on Critical Fields in $Zn_{x}Sb_{y}Cr_{z}Se_{4}$
Autorzy:
Malicka, E.
Groń, T.
Duda, H.
Pacyna, A.
Krok-Kowalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1791371.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Kz
75.30.Et
Opis:
The electrical and complex ac dynamic magnetic susceptibility measurements were used to study an influence of temperature on critical fields in single-crystalline $Zn_{x}Sb_{y}Cr_{z}Se_{4}$ spinel system with y = 0.11, 0.16 and 0.20. The p-type conduction and a shift both of the Néel temperature $T_{N}$ to lower temperatures and a susceptibility peak at $T_{m}$ in the paramagnetic region - to higher temperatures were established. Below $T_{N}$ the magnetic field dependence of susceptibility, $χ_{ac}(H)$, shows two peaks. First peak at the critical field $H_{c1}$ slightly decreases with temperature and remains almost constant as Sb content increases. Second peak at the critical field $H_{c2}$ drops rapidly with temperature and remains almost unchanged as Sb content increases. At $T_{N}$ both critical fields disappear.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 964-966
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of 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:
Magnetic Ordering of RAgSb$\text{}_{2}$ Compounds
Autorzy:
André, G.
Bourée, F.
Kolenda, M.
Leśniewska, B.
Oleś, A.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/2013392.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.50.Ee
Opis:
The magnetic structures of the polycrystalline samples of RAgSb$\text{}_{2}$ (R=Ce, Pr, Nd, Tb-Tm) are determined. All compounds crystallize in the tetragonal ZrCuSi$\text{}_{2}$-type of crystal structure and except CeAgSb$\text{}_{2}$ they are antiferromagnets with a Néel temperature of 11 K for R = Tb and 2 K for Tm. CeAgSb$\text{}_{2}$ below T$\text{}_{C}$=9.5 K is ferromagnet with the magnetic moment equal to 0.33μ$\text{}_{B}$ and parallel to c-axis. In NdAgSb$\text{}_{2}$ the sine modulated magnetic ordering described by the wave vector k = (0.5435,0,0) is observed. Below T$\text{}_{N}$ a collinear antiferromagnetic structure with the magnetic (a,a,2c) for R = Pr and (2a,a,c) for R = Tb, Dy, Ho, and Er is observed. For Ho-compound with an increase in temperature the coexistence of two structures is observed: commensurate collinear and incommensurate sine modulated. In TmAgSb$\text{}_{2}$ the coexistence of the two phases is observed at T = 1.4 K. With an increase in temperature only the incommensurate phase stays.zapisz i
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 771-774
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of RRhGe (R = Dy and Tm) Compounds
Autorzy:
Bażela, W.
Hofmann, M.
Baran, S.
Penc, B.
Szytuła, A.
Zygmunt, A.
Powiązania:
https://bibliotekanauki.pl/articles/2013666.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.50.Ee
Opis:
The magnetic properties of the ternary intermetallic RRhGe (R = Dy and Tm) were investigated by magnetic and neutron diffraction measurements. These compounds crystallize in a TiNiSi-type orthorhombic structure and are antiferromagnets with the Néel temperature 20 K (R = Dy) and 6.2 K (R = Tm). The neutron diffraction data reveal that the magnetic order in TmRhGe is collinear with the magnetic unit doubled along the b-axis respective to the crystal one.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 819-822
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of RCuGe (R=Pr, Nd, Gd, Tb, Dy, Ho, Er) Compounds
Autorzy:
Baran, S.
Leciejewicz, J.
Stüsser, N.
Szytuła, A.
Tomkowicz, Z.
Zygmunt, A.
Powiązania:
https://bibliotekanauki.pl/articles/1964562.pdf
Data publikacji:
1997-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.50.Ee
Opis:
The magnetic properties including the magnetic structure were determined by magnetometric and neutron diffraction measurements of the polycrystalline samples. RCuGe compounds are antiferromagnets at low temperatures, with T$\text{}_{N}$ ranging from 2.2 K for R = Pr to 17 K for R = Gd. The external magnetic field causes a change in the type of the magnetic ordering from antiferro- to ferromagnetic state. From the neutron diffraction data the magnetic structure of all RCuGe compounds are determined. In the case of ErCuGe below T$\text{}_{N}$ an additional phase transition is observed. The obtained experimental data are discussed in terms of an exchange interaction of the RKKY-type and crystalline electric field.
Źródło:
Acta Physica Polonica A; 1997, 92, 2; 271-275
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:
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:
Effect of Heavy Ion Irradiation on the Magnetic Properties of CuGeO$\text{}_{3}$
Autorzy:
Gładczuk, L.
Mosiniewicz-Szablewska, E.
Szymczak, R.
Baran, M.
Dąbkowska, H. A.
Choiński, J.
Czosnyka, T.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2013715.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Ee
76.30.Da
Opis:
The influence of heavy ion irradiation on the magnetic properties of the spin-Peierls compound CuGeO$\text{}_{3}$ has been investigated by means of the electron paramagnetic resonance, the spontaneous magnetization, and the low field ac susceptibility. The measurements were performed on the CuGeO$\text{}_{3}$ single crystals before and after irradiation with 80 MeV oxygen ions in the wide temperature range of 2-300 K. It was found that the irradiation induced an increase in the EPR signal intensity, magnetization, and susceptibility of this material. It was also shown that the irradiation does not lead to a decrease in the spin-Peierls transition temperature and to the formation of an antiferromagnetic phase which is expected to appear in disordered spin-Peierls systems.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 871-874
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Neutron Irradiation on the EPR Spectra of CuGeO$\text{}_{3}$
Autorzy:
Mosiniewicz-Szablewska, E.
Gładczuk, L.
Dąbkowska, H. A.
Pytel, B.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2013725.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Ee
76.30.Da
Opis:
The influence of neutron irradiation on the electron paramagnetic resonance spectra of the spin-Peierls compound CuGeO$\text{}_{3}$ was investigated in the wide temperature range 2-300 K. It was found that the irradiation induced appreciable changes in the EPR signal intensity, resonance line width and g-factor of this material. It was also shown that the irradiation leads to a decrease in the spin-Peierls transition temperature. For higher irradiation doses, an antiferromagnetically ordered phase can be observed at lower temperatures. This phase coexists with the spin-Peierls phase. The observed decrease in the spin-Peierls transition temperature after irradiation may be associated with some changes in topological and chemical short-range order or with the transmutation of the fraction of $\text{}^{63}$Cu in the $\text{}^{63}$Cu(n,α)$\text{}^{60}$Co reaction.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 897-900
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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:
Substitution effects on the magnetic properties of Fe-containing chalcogenides with NiAs-type structures
Autorzy:
Baranov, N.
Selezneva, N.
Sherokalova, E.
Gubkin, A.
Sherstobitov, A.
Shishkin, D.
Powiązania:
https://bibliotekanauki.pl/articles/1050741.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.50.Vv
75.60.-d
Opis:
The changes in the magnetization processes caused by Se for S substitutions in the layered chalcogenide compounds Fe_{x}TiS_{2-y}Se_{y} (x=0.5, 0.66) with antiferromagnetic (AF) and ferrimagnetic (FI) orderings, respectively, have been studied by using the magnetization and magnetoresistance measurements. Unusually high values of the coercive fields (H_{c} up to 56 kOe) have been observed at low temperatures in Fe_{0.5}TiS_{2-y}Se_{y} with the Se content y<0.5, which is ascribed to the presence of an unquenched orbital moment on Fe ions and to the formation of a magnetically heterogeneous state in the vicinity of H_{c}. The Se for S substitution in Fe_{0.66}TiS_{2-y}Se_{y} leads to the transition from the FI to AF state and to non-monotonous change of H_{c} with a maximal value 22 kOe an y=0.5. The changes in the magnetic state of Fe_{x}TiS_{2-y}Se_{y} are suggested to be strongly affected by the distribution of Fe ions and vacancies in cationic layers.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 447-449
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of $TbFe_{0.25}Ge_2,$ $TbSn_{0.4}Ge_{1.4}$ and $NdSn_{0.6}Ge_{1.775}$ Compounds
Autorzy:
Gil, A.
Duraj, R.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1419610.pdf
Data publikacji:
2012-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
75.40.Cx
75.47.Np
Opis:
The magnetic data of $TbFe_{0.25}Ge_2,$ $TbSn_{0.4}Ge_{1.4}$ and $NdSn_{0.6}Ge_{1.775}$ compounds are reported. These compounds crystallize in the orthorhombic crystal structures described by the space group Cmcm (No. 63) and they are antiferromagnets with the Néel temperatures equal to 19.5, 22 and 3.7 K, respectively.
Źródło:
Acta Physica Polonica A; 2012, 122, 2; 394-395
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effects of the Random Transverse Crystal Field on the Spin-1 Model
Autorzy:
Albayrak, E.
Powiązania:
https://bibliotekanauki.pl/articles/1399269.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Hk
75.30.Kz
75.50.Gg
Opis:
The effects of random transverse crystal field are investigated in the mean-field approximation on the spin-1 model. The transverse crystal field is applied on a lattice in a bimodal random distribution with a tunable parameter adjusting the strength of one mode with respect to the other one. Then, the phase diagrams are calculated on the reduced temperature-transverse crystal field planes for given values of probability p and coordination number q at zero external magnetic field h. It was found that the model gives both second- and first-order phase transitions and tricritical points which is a well-known behavior of the spin-1 model. In addition, the model also yields critical end points and end points for the first-order phase transition lines for appropriate p values.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 818-822
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:
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:
The Effect on Highly Cr-Substituted Manganite Nd$\text{}_{0.6}$C a$\text{}_{0.4}$(Mn$\text{}_{0.5}$Cr$\text{}_{0.5}$)O$\text{}_{3}$
Autorzy:
Gamari-Seale, H.
Troyanchuk, I. O.
Bushinsky, M. V.
Stefanopoulos, K. L.
Hernandez-Velasco, J.
Powiązania:
https://bibliotekanauki.pl/articles/2037098.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.25.+z
75.30.Kz
75.47.Lx
Opis:
Neutron powder-diffraction experiments on the highly Cr-substituted manganite, Nd$\text{}_{0.6}$Ca$\text{}_{0.4}$(Mn$\text{}_{0.5}$Cr$\text{}_{0.5}$)O$\text{}_{3}$, at different temperatures and fields reveal that the structure retains the charge exchange-type of the parent compound, Nd$\text{}_{0.6}$Ca$\text{}_{0.4}$MnO$\text{}_{3}$. It is antiferromagnetic below 200 K and becomes a canted antiferromagnet below 50 K. The Mn and Cr form zig-zag ferromagnetic chains coupled antiferromagnetically in the ac-plane. These are stacked along the b-axis with opposite spins.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 81-86
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:
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:
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:
Magnetocaloric Effect in Nanostructured $Pr_2Fe_{17}$ and $Nd_2Fe_{17}$ Synthesized by High-Energy Ball-Milling
Autorzy:
Alvarez, P.
Sánchez-Marcos, J.
Sanchez Llamazares, J.
Franco, V.
Reiffers, M.
Blanco, J.
Gorria, P.
Powiązania:
https://bibliotekanauki.pl/articles/1534200.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
75.50.Tt
75.30.Kz
Opis:
Nanocrystalline $Pr_2Fe_{17}$ and $Nd_2Fe_{17}$ powders with rhombohedral $Th_2Zn_{17}$-type crystal structure and average particle sizes around 20 nm have been obtained by high-energy ball milling. While the bulk alloys show a well-defined and sharp drop in the low-field magnetization curve at the Curie temperature, $T_{C}$ = 285 K (Pr) and 335 K (Nd), the ball-milled samples exhibit a substantial broadening of the ferro-to-paramagnetic transition due to a considerable augmentation of the disordered inter-grain boundaries. The latter results in an increase of more than 25% in the values of the full width at half maximum of the temperature dependence of the magnetic entropy change maintaining almost unchanged the relative cooling power.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 867-869
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified Equation of Motion Approach for Ferromagnetic Systems
Autorzy:
Górski, G.
Mizia, J.
Kucab, K.
Powiązania:
https://bibliotekanauki.pl/articles/1384824.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
75.10.Lp
75.30.Kz
Opis:
The key problem in using the dynamical mean-field theory is finding the appropriate solution to the single impurity Anderson model. We use the modified equation of motion method based on differentiation over two time variables. In such approach we obtain correct description of the Kondo effect not only for systems symmetrical with respect to the half-filled point but also for the systems without symmetry in a half filled point and for broad range of electron concentrations like e.g. the ferromagnetic systems. For the reason of these advantages we investigate in this report dependence of the system magnetic moment on carrier concentration using our modified equation of motion method. We also analyze influence of asymmetric densities of states on ferromagnetic alignment. Our results are compared with dynamical mean-field theory-quantum Monte Carlo calculations and with Hubbard I and III approximations.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 207-209
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:
Inverse magnetocaloric effect in spin-1/2 Fishers super-exchange antiferromagnet
Autorzy:
Gálisová, L.
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1052954.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.30.Et
75.30.Sg
75.30.Kz
Opis:
The isothermal entropy change and the adiabatic temperature change are rigorously calculated for the exactly solved spin-1/2 Fisher's super-exchange antiferromagnet in order to examine magnetocaloric properties of the model in a vicinity of the second-order phase transition. It is shown that the large inverse magnetocaloric effect occurs around the temperature interval T_c(h≠0) < T < T_c(h=0) for any magnetic-field change Δh:0 → h. The most pronounced inverse magnetocaloric effect can be found for the magnetic-field change, which coincides with the critical field of a zero-temperature phase transition from the antiferromagnetically ordered ground state to the paramagnetic one.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 627-629
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Transport Properties of Carbon-Doped $EuB_6$
Autorzy:
Batkova, M.
Batko, I.
Filipov, V.
Flachbart, K.
Sechovský, V.
Shitsevalova, N.
Šantavá, E.
Šebek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1534309.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Kz
72.15.Gd
75.47.Gk
Opis:
In the presented work we report electrical, magnetic and thermal properties of $EuB_{6-x}C_{x}$ single crystals with an estimated value of x ≈ 0.07. Our studies reveal an antiferromagnetic phase transition at $T_{N}$ ≈ 6.7 K. Electrical resistivity at zero magnetic field shows a pronounced resistivity maximum at $T_{M}$ ≈ 7 K, just above the antiferromagnetic phase transition temperature. With increasing applied magnetic field the maximum moves to lower temperature and becomes totally suppressed at the field of 9 T. Observed magnetoresistance is negative in the whole studied temperature range 2-20 K, yielding a ratio of ρ(0 T, 7 K)/ρ(9 T, 7 K) ≈ 2.5. The origin of such magnetoresistance is associated with formation of mixed magnetic structure in the system due to fluctuation of carbon concentration.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 893-894
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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:
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:
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:
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:
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:
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:
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:
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:
Mössbauer and X-ray Diffraction Studies of Zr$\text{}_{1-x}$Ti$\text{}_{x}$Fe$\text{}_{2}$ Laves Phase Compounds
Autorzy:
Budzyński, M.
Sarzyński, J.
Surowiec, Z.
Wiertel, M.
Powiązania:
https://bibliotekanauki.pl/articles/2028966.pdf
Data publikacji:
2001-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.30.Gs
77.80.Bh
75.30.Kz
Opis:
Mössbauer spectroscopy of $\text{}^{57}$Fe and X-ray diffraction measurements in the Zr$\text{}_{1-x}$Ti$\text{}_{x}$Fe$\text{}_{2}$ phase have been made. Our X-ray diffraction spectra revealed that the samples have the cubic C15 crystal structure for low Ti concentration and the hexagonal C14 structure for high Ti concentration. In the range of 0.2≤x≤0.5 a mixture of both structures occurs. The investigated compounds are paramagnetic at RT for x>0.80 and magnetic for x
Źródło:
Acta Physica Polonica A; 2001, 100, 5; 717-722
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of EuBaCo$\text{}_{2}$O$\text{}_{5.5}$ Single Crystals
Autorzy:
Baran, M.
Barilo, S. N.
Bychkov, G. L.
Gatalskaya, V. I.
Kurochkin, L. A.
Shiryaev, S. V.
Szymczak, R.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/2037131.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.50.Dd
75.30.Gw
75.30.Kz
Opis:
The static magnetization of the EuBaCo$\text{}_{2}$O$\text{}_{5.5}$ single crystals was measured from helium to room temperatures for two configurations of the applied field: parallel and perpendicular to the c-axis. The compound is antiferromagnetic from helium temperature to about 210 K. In low temperature region (below 45 K) the antiferromagnetism coexists with a spin-glass-like state. The metamagnetic field-induced phase transition was observed in the antiferromagnetic phase for magnetic field applied perpendicular to the c-axis. The spontaneous phase transition from antiferromagnetic to weak ferromagnetic phase was established to be of the first order. This transition is accompanied by the appearance of the intermediate state. The weak ferromagnetic phase exists up to T$\text{}_{c}$=240 K.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 209-214
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:
AC Susceptibility Studies of Phase Transitions and Magnetic Relaxation: Conventional, Molecular and Low-Dimensional Magnets
Autorzy:
Bałanda, M.
Powiązania:
https://bibliotekanauki.pl/articles/1399022.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.30.Kz
75.40.Gb
75.50.-y
Opis:
The paper presents the review of AC susceptibility measurements in study of magnetic phase transitions and spin dynamics. Examples of several types of phase transitions in conventional and molecular magnets are shown. The phenomenon of magnetic relaxation is briefly ascribed and illustrated with results on relaxation in low-dimensional molecular magnets, such as single molecule magnets, single chain magnets and quasi 1-dimensional systems showing magnetic phase transition to the long-range ordered phase. The following experimental possibilities of the AC technique, which allow to get insight into properties of novel magnetic materials are mentioned: (i) change of the AC field amplitude (in order to distinguish ferro-(ferri) and antiferromagnets); (ii) use of a static field H_{DC} (to conclude on the type of magnetic order and to study the phase diagram); (iii) measurement of nonlinear susceptibilities (to conclude on the type of phase transition); (iv) probing the dependence of both components of susceptibility on frequency of the AC field (to study magnetic relaxation); (v) tests of the DC field effect on the frequency dependence of χ_{AC} (to analyze the possibility of blocking or reentrant spin-glass transition).
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 964-976
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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:
Magnetism and Specific Heat of TmRhX (X = Ga, Ge) Compounds
Autorzy:
Baran, S.
Przewoźnik, J.
Szytuła, A.
Powiązania:
https://bibliotekanauki.pl/articles/1399029.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.-m
75.30.kz
75.40.Cx
75.47.Np
Opis:
Magnetic and specific heat data of the TmRhX (X = Ga, Ge) compounds are reported. These compounds crystallize in an orthorhombic crystal structure of the TiNiSi-type (space group Pnma). Magnetic data indicate that the compounds are antiferromagnets with the Néel temperature $T_{N}$ equal to 3.9 K for TmRhGa and 6.0 K for TmRhGe. Magnetic susceptibility of TmRhGe has an additional peak at $T_{t}$ = 10.6 K. In TmRhGe temperature dependence of χ"(T), the positions of both the peaks at $T_{N}$ and $T_{t}$ change with frequency indicating a relaxation process. These data suggest that with the decreasing temperature, first a cluster glass state and next the long-range aniferromagnetic order exists.
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 998-1001
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:
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:
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:
Low Temperature Magnetic Properties of $Pr_{0.7}(Ca,Sr)_{0.3}CoO_{3}$ Oxides
Autorzy:
Deac, I.
Vlădescu, A.
Balasz, I.
Tunyagi, A.
Tetean, R.
Powiązania:
https://bibliotekanauki.pl/articles/1503539.pdf
Data publikacji:
2011-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
75.30.Kz
75.30.Sg
73.43.Qt
Opis:
We have investigated magnetic and magnetocaloric properties of $Pr_{0.7}(Ca_{1-x}Sr_{x})_{0.3}CoO_{3},$ when the average size of the interpolated cation was changed. $Pr_{0.7}Ca_{0.3}CoO_{3}$ has an orthorhombic Pnma symmetry and it shows a magnetic cluster-glass behavior below 70 K. When Sr partially replaces Ca in this compound, its magnetic properties are improved, and it begins to have ferromagnetic-like behavior. The magnetic transition temperature, gradually, increases with increasing Sr content, up to 170 K, for x=1. The electrical conduction also improved when Sr content increased. All the samples show negative magnetoresitance. Magnetic entropy change $\Delta S_{M}$ was estimated from isothermal magnetization data. We have found that it had higher values for the samples with x>0.5, around 1 J/kg K for Δ B=4 T, with reasonable good relative cooling power.
Źródło:
Acta Physica Polonica A; 2011, 120, 2; 306-310
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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:
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:
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:
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:
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:
Magnetocaloric Effect in $NdNi_4Si$ Compound
Autorzy:
Falkowski, M.
Toliński, T.
Kowalczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/1429061.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Kz
75.47.Np
75.40.-s
Opis:
On the basis of the thermodynamic approach, we report the magnetocaloric properties of the ternary ferromagnetic $NdNi_4Si$ compound with magnetic phase transition temperature $T_{C}$ at 8 K. The saturated magnetic moment in H = 9 T is equal to 1.5 $μ_{B}$/f.u. at 4.2 K and the compound crystallizes in the hexagonal $CaCu_5$-type structure (space group P6/mmm). The magnetocaloric effect was calculated in terms of the isothermal magnetic entropy change Δ $S_{M}$ as well as the adiabatic temperature change Δ $T_{ad}$ using the specific heat data and magnetization measurements. Within the second order phase transition significant values of these parameters have been observed.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1290-1292
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:
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:
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 Phase Transitions in Intermetallic GdNi$\text{}_{5-x}$Sn$\text{}_{1+x}$ and TbNi$\text{}_{5-x}$Sn$\text{}_{1+x}$ Compounds
Autorzy:
Baran, M.
Szymczak, H.
Szymczak, R.
Romaka, L.
Skolozdra, R.
Powiązania:
https://bibliotekanauki.pl/articles/1964576.pdf
Data publikacji:
1997-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.20.En
75.30.Kz
75.60.Ej
75.30.Cr
Opis:
Magnetization measurements were performed for intermetallic compounds GdNi$\text{}_{5-x}$Sn$\text{}_{1+x}$ and TbNi$\text{}_{5-x}$Sn$\text{}_{1+x}$ in the temperature range from 4.5 K to 280 K and in magnetic field up to 50 kOe. Complex magnetic phase diagram was revealed for both compounds. The results are discussed assuming three-sublattice magnetic structure and partial disordering of the structure.
Źródło:
Acta Physica Polonica A; 1997, 92, 2; 295-298
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:
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:
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:
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:
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
Wyświetlanie 1-100 z 142

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