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.-Cr" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 82
Tytuł:
Susceptibility of the Rare Earth Ternary RNiSi$\text{}_{2}$ and RNiGe$\text{}_{2}$ Compounds
Autorzy:
Gil, A.
Szytuła, A.
Tomkowicz, Z.
Wojciechowski, K.
Zygmunt, A.
Powiązania:
https://bibliotekanauki.pl/articles/1929852.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
Opis:
The ternary silicides and germanides RNiX$\text{}_{2}$ (R - rare earth, X = Si or Ge) with the orthorhombic CeNiSi$\text{}_{2}$-type structure are investigated by magnetometric measurements. CeNiSi$\text{}_{2}$, CeNiGe$\text{}_{2}$ and SmNiGe$\text{}_{2}$ have a nonmagnetic state in low temperatures. The compounds with R = Pr and Nd are ferromagnets while those containing R = Gd-Er are antiferromagnets. The de Gennes scaling of the Néel temperatures indicates a strong influence of the crystalline-electric field effects.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 271-274
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of Thorium Ferricyanide
Autorzy:
Göbl, R.
Zentková, M.
Kavečanský, V.
Kováč, J.
Zentko, A.
Powiązania:
https://bibliotekanauki.pl/articles/2013694.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
Opis:
The magnetic properties of Th$\text{}_{3}$[Fe(CN)$\text{}_{6}$]·10H$\text{}_{2}$O were investigated. It was shown that this compound is antiferromagnetically ordered in the low temperature region. The observed antiferromagnetic ordering is stable only in the low field.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 835-838
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Pressure on Magnetization of (Cd$\text{}_{1-x-y}$Zn$\text{}_{y}$Mn$\text{}_{x}$)$\text{}_{3}$As$\text{}_{2}$
Autorzy:
Bednarski, H.
Cisowski, J.
Lubczyński, W.
Voiron, J.
Portal, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/1931965.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
Opis:
The influence of hydrostatic pressure up to 0.6 GPa on magnetization of (Cd$\text{}_{1-x-y}$Zn$\text{}_{y}$Mn$\text{}_{x}$)$\text{}_{3}$As$\text{}_{2}$ with various compositions was studied at 4.2 K and in magnetic fields up to 7 T. The obtained experimental data were analysed within our generalized pair approximation model, treating the total Mn-Mn interaction strength as a sum of superexchange and the Bloembergen-Rowland exchange. As a result, we obtained satisfactory agreement between our approach and experiment by introducing a pressure dependence of p-d hybridization potential V$\text{}_{pd}$ in the form V$\text{}_{pd}$ ∝ d$\text{}^{-4}$, where d is the Mn-As bond length which decreases with pressure.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 205-208
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:
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 of Layer-Type Compounds TlGdS$\text{}_{2}$ and TlGdSe$\text{}_{2}$
Autorzy:
Duczmal, M.
Pawlak, L.
Pokrzywnicki, S.
Powiązania:
https://bibliotekanauki.pl/articles/2013695.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
75.30.Cr
Opis:
Ternary thallium lanthanide dichalcogenides TlLnX$\text{}_{2}$ (X = S, Se, or Te; Ln = lanthanide, except Ce and Pr) crystallize in the rhombohedral structure of α-NaFeO$\text{}_{2}$ type ($R\overline{3}m$). Their crystal lattice consists of the layers of Ln$\text{}^{3+}$ ions separated by three layers of the non-magnetic ions (-Ln-X-Tl-X-Ln-). The magnetization was measured in the field range 0-14 T. The molecular field constants λ$\text{}_{m}$ were estimated by fitting the Brillouin function to the experimental magnetization plots. The difference between the λ$\text{}_{m}$ values for the thallium gadolinium sulphide and the selenide corresponds to the different character of Gd-S and Gd-Se bonds and gives rise to the different J$\text{}_{1}$ and J$\text{}_{2}$ exchange integrals.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 839-842
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Simple Localized-Itinerant Model for PrAl$\text{}_{3}$: Crystal Field and Exchange Effects
Autorzy:
Von Ranke, P. J.
Palermo, L.
Da Silva, X. A.
Powiązania:
https://bibliotekanauki.pl/articles/1891680.pdf
Data publikacji:
1991-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Dg
75.30.Cr
Opis:
We present a simple magnetic model for PrAl$\text{}_{3}$. The effects of crystal field are treated using a reduced set of levels and the corresponding wave functions are extracted from the actual crystal field levels of Pr$\text{}^{+3}$ in a hexagonal symmetry. The exchange between 4f- and conduction-electrons are dealt within a molecular field approximation. An analytical magnetic state equation is derived and the magnetic behaviour discussed. The parameters of the model are estimated from a fitting of the inverse susceptibility of PrAl$\text{}_{3}$ given in the literature.
Źródło:
Acta Physica Polonica A; 1991, 80, 4; 583-590
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometrically Frustrated Kagome Lattice with Chemical Disorder
Autorzy:
Szymczak, R.
Baran, M.
Fink-Finowicki, J.
Krzymanska, B.
Aleshkevych, P.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/1813765.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.20.-g
Opis:
The effect of nonmagnetic $Mg^{2+}$ and magnetic $Co^{2+}$ doping in Kagome compounds was investigated using DC magnetic susceptibility. The main effect of doping is to change the crystal field parameters. It was shown that $Co^{2+}$ doping increases considerably crystal field parameters in $Ni_3V_2O_8$ while doping with nonmagnetic $Mg^{2+}$ ions decreases considerably crystal field parameters in $Co_3V_2O_8$ crystals.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 413-416
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theory of Strongly Correlated Systems in the Limit of Large On-Site Coulomb Repulsion
Autorzy:
Izyumov, Yu. A.
Powiązania:
https://bibliotekanauki.pl/articles/1860989.pdf
Data publikacji:
1994-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Lp
75.30.Cr
Opis:
A strongly correlated electronic system is studied within the framework of the t-J model with the help of diagram technique for the Hubbard X-operators. The summing of some series of diagrams is suggested, corresponding to the following three types of approximations: the generalized random phase approximation, the mean field approximation, and the low density approximation. In generalized random phase approximation the dynamic magnetic susceptibility of paramagnetic phase is calculated, and boundaries of stability of this phase are found on the plane of Hamiltonian parameters and electron concentration n. It is shown that at some critical concentration n$\text{}_{c}$ the system undergoes a crossover from the itinerant magnetism (n < $\text{}n_{c}$) to the magnetism with localized magnetic moments (n > $\text{}n_{c}$). Simultaneously, the system transfers from the Fermi-liquid behaviour to the regime of strong electron correlations with nonquasiparticle states. In mean field approximation equations for the order parameters were derived and phase transitions temperatures in a ferromagnetic and antiferromagnetic phases were obtained. In low density approximation a state of the saturated ferromagnetism was investigated and a critical concentration n$\text{}_{s}$ was calculated when the nonsaturated ferromagnetism follows the saturated ferromagnetism.
Źródło:
Acta Physica Polonica A; 1994, 85, 1; 103-115
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of DyTe
Autorzy:
Pokrzywnicki, S.
Duczmal, M.
Pawlak, L.
Nenkov, K. A.
Powiązania:
https://bibliotekanauki.pl/articles/1964659.pdf
Data publikacji:
1997-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Ee
75.30.Cr
Opis:
Dysprosium monotelluride is a metallic substance with one valence electron per formula unit belonging to the conduction band. It crystallizes in the defected NaCl-type structure (a= 0.6070 nm) with cation deficiency in the metal sublattice. AC and DC susceptibilities exhibit a maximum at 15 K and a second maximum at higher temperatures which position is field dependent.
Źródło:
Acta Physica Polonica A; 1997, 92, 2; 351-354
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiband s-f Model for Pseudobinary Intermetalic Gd(Al$\text{}_{1-x}$Me$\text{}_{x}$)$\text{}_{2}$ Alloys. II. Me=Pb, Bi, Si, Sb
Autorzy:
Matlak, M.
Zieliński, J.
Powiązania:
https://bibliotekanauki.pl/articles/1887586.pdf
Data publikacji:
1991-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.20.En
Opis:
With the use of the formulae derived in the preceding paper we calculate the Curie temperature and the magnetic moment as functions of the concentration x for Gd(Al$\text{}_{1-x}$Me$\text{}_{x}$)$\text{}_{2}$ (Me = Pb, Bi, Si, Sb) alloys. The agreement with the recent experimental data is relatively good.
Źródło:
Acta Physica Polonica A; 1991, 79, 5; 717-719
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EPR Spectra of Cr in CdTe Crystals
Autorzy:
Stefaniuk, I.
Bester, M.
Virt, I. S.
Kuzma, M.
Powiązania:
https://bibliotekanauki.pl/articles/2043654.pdf
Data publikacji:
2005-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Cr
Opis:
The EPR studies of CdTe:Cr were performed on X-band (9.6 GHz) spectrometer at room temperature. Single CdTe crystals were doped by chromium Cr in the synthesis process. The spectra observed were resolved into two spectra. The first one consisted of very broad line (Δ B=100 mT) and the second one showed a typical fine structure. The complete angular dependence measurements were obtained. The fine structure of Cr$\text{}^{2+}$ or Cr$\text{}^{3+}$ ions was assumed and simulated. It follows from the theoretical analysis of the obtained spectra that degree of ionization of the chromium Cr dopant is 3+.
Źródło:
Acta Physica Polonica A; 2005, 108, 2; 413-418
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:
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:
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:
The J₁-J₂ Model on the Anisotropic Triangular and the Square Lattice: Similarities and Differences
Autorzy:
Schmidt, B.
Thalmeier, P.
Powiązania:
https://bibliotekanauki.pl/articles/1385520.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Cr
75.30.Ds
Opis:
The Heisenberg model on a triangular lattice is a prime example for a geometrically frustrated spin system. However most experimentally accessible compounds have spatially anisotropic exchange interactions. As a function of this anisotropy, ground states with different magnetic properties can be realized. On the other hand, the J₁-J₂ model on the square lattice is a well-known example for frustration induced by competing exchange. The classical phase diagrams of the two models are related in a broad range of the control parameter ϕ=$tan^{-1}$(J₂/J₁). In both cases three different types of ground states are realized, each model having a ferromagnetic and an antiferromagnetic region in the phase diagram, and a third phase with columnar magnetic order for the square lattice and an in general incommensurate spiral structure for the triangular lattice. Quantum effects lift degeneracies in the non-FM phases and lead to additional nonmagnetic regions in the phase diagrams. The contribution of zero point fluctuations to ground state energy, wave vector, and ordered moment is discussed.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 324-326
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Pressure on Magnetic Properties of $(NH_3OH)_2CoF_4$ Fluoro-Metal Complex
Autorzy:
Jagličić, Z.
Zentková, M.
Mihalik, M.
Drofenik, M.
Kristl, M.
Dojer, B.
Kasunič, M.
Golobič, A.
Jagodič, M.
Arnold, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1535548.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Lx
75.30.Cr
75.30.Kz
Opis:
Effect of pressure on magnetic properties of a bulk fluoro-metal complex $(NH_3OH)_2MF_4$ was studied. Magnetization measurements suggest that a ferromagnetic transition at $T_{C1}$ = 47 K is followed by a ferrimagnetic one at $T_{C2}$ = 3 K. Both transition temperatures are pressure dependent with the pressure coefficients $dT_{C1}$/ dp = - 2.6 K/GPa and $dT_{C2}$/ dp = 0.26 K/GPa. The opposite sign of the coefficients is an additional indication of a different nature (ferromagnetic/antiferromagnetic) of these two transitions. The effect of pressure on low field magnetization and exchange bias phenomena is small but still visible.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 1074-1075
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Field Effects in Frustrated Low-Dimensional Magnets
Autorzy:
Schmidt, B.
Siahatgar, M.
Thalmeier, P.
Powiązania:
https://bibliotekanauki.pl/articles/1427076.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
75.30.Cr
75.30.Ds
Opis:
We investigate the frustrated two-dimensional S = 1/2 next nearest neighbor anisotropic Heisenberg antiferromagnet on a square lattice as described by the $J_{1a,b} - J_2$ model. We use spin-wave theory and exact diagonalization for finite tiles including a new method for the finite size scaling procedure. We present results obtained from the extension of our numerical method to finite magnetic fields as well as from spin-wave theory. The induced uniform and the staggered moment in the antiferromagnetically ordered phases in the presence of a magnetic field are calculated. They deviate strongly from classical behaviour depending on frustration ratio $J_2//J_{1a,b}$ and the $J_{1a,b}$ exchange anisotropy. The magnetization becomes strongly nonlinear and is suppressed from the classical value. This is due to enhanced quantum fluctuations already at moderate frustration.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1089-1091
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:
Paramagnetism of Cu_3RE_2W_4O_{18} Semiconductors (RE = Gd, Dy-Er)
Autorzy:
Groń, T.
Tomaszewicz, E.
Duda, H.
Mazur, S.
Powiązania:
https://bibliotekanauki.pl/articles/1399149.pdf
Data publikacji:
2013-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.20.-g
75.30.Cr
Opis:
$Cu_3RE_2W_4O_{18}$ tungstates (RE = Gd, Dy-Er) are paramagnets in the temperature range 4.2-300 K visible also in the absence of the energy losses in the curve of the imaginary part of magnetic susceptibility, χ". The negative values of the paramagnetic Curie-Weiss temperature, θ, may suggest the weak antiferromagnetic coupling below 4.2 K. The temperature independent component of magnetic susceptibility has a positive value indicating a domination of the Van Vleck contribution. Calculations of the effective number of the Bohr magnetons revealed that the orbital contribution to the magnetic moment comes mainly from the $RE^{3+}$ ions.
Źródło:
Acta Physica Polonica A; 2013, 124, 5; 885-887
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Details of Magnetic Properties in $Pb(Fe_{1/2}Nb_{1/2})O_{3}$
Autorzy:
Maryško, M.
Laguta, V.
Raevski, I.
Powiązania:
https://bibliotekanauki.pl/articles/1372364.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.85.+t
75.50.Ee
Opis:
For $Pb(Fe_{0.5}Nb_{0.5})O_{3}$ the χ(T) and m(H) measurements up to 70 kOe were performed with the aim to estimate the antiferromagnetic (AFM) and superantiferromagnetic (SAF) contribution to χ(T). Below $T_{N}$ the increase of χ(T) is attributed to a small part of $Fe^{3+}$ ions in the SAF clusters. For high fields the suppression of the AFM and enhancement of the SAF susceptibility was observed. An inflection point of the m(H) curves below the Néel point suggests the presence of a spin reorientation process connected with the AFM phase.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 376-377
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Wave Excitations and Fluctuations of the Exchange Interaction in Amorphous Fe$\text{}_{1-x}$Zr$\text{}_{x}$ Alloys
Autorzy:
Kossacki, P.
Stobiecki, T.
Szymczak, H.
Powiązania:
https://bibliotekanauki.pl/articles/1929351.pdf
Data publikacji:
1993-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Cr
75.50.Kj
75.70.-i
Opis:
Detailed magnetization measurements were performed on amorphous Fe$\text{}_{1-x}$Zr$\text{}_{x}$ alloys with 0.14 ≤ x ≤ 0.48 at temperatures ranging from 4.2 K to the Curie temperature in external magnetic field up to 5 T. An analysis of the experimental data reveals that' the fluctuations of the exchange integral resulting from the structural disorder give important contribution to the thermal demagnetization and high-field susceptibility of Fe-rich alloys. For Zr-rich alloys the effect of fluctuations of the exchange integral is negligible and thermal demagnetization is described in terms of spin-wave excitations. No Stoner single-particle excitations were observed for alloys with x > 0.14.
Źródło:
Acta Physica Polonica A; 1993, 83, 6; 785-791
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 82

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