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Showing papers on "Curie–Weiss law published in 1980"


Journal ArticleDOI
TL;DR: In this paper, a spin-fluctuation theory was applied to iron and nickel for a discussion of their magnetic and thermodynamical properties at finite temperatures with a slight extension including the effect of charge fields within the steepest-descent approximation.
Abstract: A spin-fluctuation theory developed previously by the present author is applied to iron and nickel for a discussion of their magnetic and thermodynamical properties at finite temperatures with a slight extension including the effect of charge fields within the steepest-descent approximation. The Curie temperature, the average magnetization, the amplitude of local magnetic moments, the spin susceptibility and the specific heat are calculated, which are in qualitatively, or semi-quantitatively good agreement with experimental data.

101 citations


Journal ArticleDOI
TL;DR: In this article, a magnetic phase diagram for CeB6 has been proposed and the paramagnetic susceptibility has been analyzed by assuming appropriate values of crystal-field splitting and exchange interactions.

93 citations


Journal ArticleDOI
TL;DR: In this paper, the susceptibility, magnetization, electrical resistivity and thermopower of Y 4 Co 3 have been measured and a Curie temperature of (8±1) K has been observed.

55 citations



Journal ArticleDOI
TL;DR: In this paper, the chemical short-range order of metallic glasses is discussed and it is shown that structural disorder has minor effects on the shape of the magnetization curve, on the magnetic moments and Curie temperatures.

29 citations


Journal ArticleDOI
TL;DR: In this paper, the Curie temperatures of 25 amorphous alloy systems involving a binary metal together with metalloids have been fitted to phenomenological equations based on a localized band model involving only one adjustable parameter to describe the variation of Curie temperature with metal composition.
Abstract: The Curie temperatures of 25 amorphous alloy systems involving a binary metal together with metalloids have been fitted to phenomenological equations based on a localized band model involving only one adjustable parameter to describe the variation of Curie temperature with metal composition.

28 citations


Journal ArticleDOI
TL;DR: The saturation magnetic moment µs, the Curie temperature Tc, and the high temperature susceptibility were measured in the amorphous alloy system (Fe1-xNix)77Si10B13 as discussed by the authors.
Abstract: The saturation magnetic moment µs, the Curie temperature Tc, and the high temperature susceptibility were measured in the amorphous alloy system (Fe1-xNix)77Si10B13. The measurements were done for temperatures above 77 K. The variation of µs and Tc with x were similar to that in other (Fe-Ni)-amorphous systems so far reported. The susceptibility was measured for specimens with 0.6x1.0. Ni77Si10B13 or x=1.0 was found to have Pauli type paramagnetism with χg=2×10-6 emu/g over the temperature range 77-500 K. The susceptibilities for other specimens followed the Curie-Weiss law well, and so the Curie constant Cg, the effective magnetic moment µeff, and the asymptotic Curie temperature Θ were determined. Cg, µeff, and Θ decreased so as to vanish at x~1.0.

22 citations


Journal ArticleDOI
E.P. Wohlfarth1
TL;DR: In this article, an account of the magnetic properties in high magnetic fields is given, where the exchange splitting energies of pure nickel and Ni-Pd alloys near the Curie points are discussed.

20 citations


Journal ArticleDOI
TL;DR: Magnetic data for R 6 Mn 23 and R 6 NM 23 H 23 (R  Tb, Dy ) are presented in this article, where the lower exchange is attributed to a diminished electron concentration brought about by electron capture by hydrogen.
Abstract: Magnetic data are presented for R 6 Mn 23 and R 6 Mn 23 H 23 ( R  Tb , Dy ). Exchange in these materials is weak compared with that in the host metal. Dy 6 Mn 23 H 23 remains paramagnetic to 4.2 K whereas the host material has a Curie temperature T c of 443 K. Hydrogenation of Tb 6 Mn 23 lowers its Curie temperature by about 230 K and decreases its magnetization by a factor of about 3. The lowered exchange is attributed to a diminished electron concentration brought about by electron capture by hydrogen. The reduced magnetization is thought to be a crystal field effect.

19 citations



Journal ArticleDOI
TL;DR: In this paper, a Landau-theory for inhomogenous ferromagnets was proposed and the following observable results were calculated in terms of the local density fluctuations: paramagnetic and ferromagnetic Curie temperatures, Curie-Weiss constant, magnetization.

Journal ArticleDOI
TL;DR: In this paper, the low-field magnetic susceptibilities and the low temperature isothermal magnetization of anhydrous NiCl 2 were analyzed based on a molecular field model, which leads to precise values for certain of the magnetic parameters.

Journal ArticleDOI
TL;DR: In this paper, the spontaneous magnetic moment, the Curie temperature T C, and the antiferro-ferromagnetic transition temperature T t, are considered for CoMnSi 1−x Ge x solid solution system.

Journal ArticleDOI
TL;DR: In this article, the effects of B and Mn contents on the magnetic moment and the Curie temperature of Co-Mn-B amorphous alloys have been studied in a wide range of b and Mn concentrations.
Abstract: The effects of B and Mn contents on the magnetic moment and the Curie temperature of Co-Mn-B amorphous alloys have been studied in a wide range of B and Mn concentrations. The magnetic moment at 4.2K decreases monotonically with increasing Mn content for the alloys with low B content, while it increases initially and then decreases similarly to the low B alloys for the alloys with high B content. Ferromagnetic moments vanish at about x=0.4 irrespective to B content. The Curie points also reach zero absolute temperature near the same Mn content. These Mn and B composition dependences of magnetic moment are analysed on the basis of the local environment model.


Journal ArticleDOI
TL;DR: The magnetic susceptibility of the alkaline earth oxo-neptunates (IV), SrNpO 3 and BaNp O 3, were measured from 4.2 K to about 300 K with a Faraday magnetic balance at different applied fields up to 13.1 kG as discussed by the authors.
Abstract: The magnetic susceptibility of the alkaline earth oxo-neptunates(IV), SrNpO 3 and BaNpO 3 , were measured from 4.2 K to about 300 K with a Faraday magnetic balance at different applied fields up to 13.1 kG. Both compounds show magnetic transitions at rather high temperatures, namely 31 and 48 K, respectively. The sharp increase in magnetization of both compounds below the transition temperatures points to ferromagnetic transitions; however, application of simple theory suggests a more complicated magnetic structure. Above the Curie temperatures both compounds display very similar paramagnetic behaviour which should be attributed to very similar crystal environment of the paramagnetic ions. The rather low magnetic moments at room temperature suggest a distortion of the cubic perowskite-structure which has already been proposed for BaNpO 3 .

Journal ArticleDOI
Takeo Jo1
TL;DR: In this article, the electronic structure in the ground state and the response to the magnetic field of Ni-Mn alloys were investigated with use of the Hartree-Fock-Coherent Potential Approximation (HF-CPA) approach.
Abstract: The electronic structure in the ground state and the response to the magnetic field of Ni–Mn alloys are investigated with use of the Hartree-Fock-Coherent Potential Approximation (HF-CPA) approach. The calculation which distinguishes Mn atoms having antiparallel moments to the bulk magnetization from those with parallel moments shows the occurrence of the second order phase transition at the critical Mn concentration from the ferromagnetic state to the spin glass state in the absence of the magnetic field. The calculated spin susceptibility and bulk magnetization as functions of the magnetic field and the Mn concentration well reproduce the recent experimental results.

Journal ArticleDOI
TL;DR: In this paper, the influence of a magnetic field on the properties of a ferroelectric semiconductor is considered in the frames of the vibronic theory and the Zeeman and Landau splittings of valence and conduction bands are taken into account.
Abstract: The influence of a magnetic field on the properties of a ferroelectric semiconductor is considered in the frames of the vibronic theory. The Zeeman and Landau splittings of valence and conduction bands are taken into account. The dependences of the Curie point, soft-mode frequencies, and other characteristics on the magnetic field are calculated. The direction of the magnetic shift of the Curie point depends on the particular relations between the quantities of the spin and cyclotron splittings. In certain cases the magnetic field can change the potential ferroelectric phase transition into a real one. [Russian Text Ignored.]

Journal ArticleDOI
Tôru Moriya1
TL;DR: In this paper, simple arguments are given to explain the Curie-Weiss susceptibility in mutually opposite extreme cases, the local moment limit and the weakly ferromagnetic limit, and the behaviors of spin fluctuations in these extremes and in the intermediate situation are illustrated.
Abstract: Simple arguments are given to explain in a unified way the two mecha­ nisms for the Curie-Weiss susceptibility in the mutually opposite extreme cases, the local moment limit and the weakly ferromagnetic limit. The behaviors of spin fluctuations in these extremes and in the intermediate situation are illustrated.

Journal ArticleDOI
J. B. Sousa1, R.P. Pinto1, M.M. Amado1, M.F. Pinheiro1, J. M. Moreira1, M.E. Braga1 
TL;DR: In this paper, high resolution data (1 : 104) is presented on the behavior of the thermal conductivity (K) of Gd near the Curie point in terms of electronic, lattice and bipolar conduction.
Abstract: 2014 High resolution data (1 : 104) is presented on the behaviour of the thermal conductivity (K) of Gd near the Curie point. The results are analysed in terms of electronic, lattice and bipolar conduction. Previous information on the electrical resistivity (p) and the temperature derivative dp/dT is also used to understand the temperature dependence of K. Detailed reference is made on the experimental method used. J. Physique 41 (1980) 573-578 JUIN 1980, Classification Physics Abstracts 72.15E

Journal ArticleDOI
TL;DR: In this article, a super exchange interaction via acetylide ion, C22−, contributes much to the total magnetic exchange for CeC2 and its solid solutions, CeXDy1−XC2.

Journal ArticleDOI
TL;DR: In this paper, the authors measured the d.c. susceptibilities and the remanent magnetization of amorphous holmium aluminosilicate (Ho2O3) 0.194(Al2O 3)0.227(SiO2)0,579.

Journal ArticleDOI
TL;DR: In this paper, the results of magnetic investigations on Sm 6 Mn 23 x Fe x compounds performed over a wide temperature range were presented, and it was found that replacing the Mn atoms in Sm 6 NM 23 and Fe atoms by Fe and Mn, respectively, causes a rapid reduction in both the Curie temperature and the magnetic moment.

Journal ArticleDOI
TL;DR: In this paper, the relation between magnetization M, field H and temperature T is satisfactorily fitted to an equation (H / M ) 0.75 = a (T - T c )+ b M 2.5 vs ( H / M 0.5, are parallel straight lines.
Abstract: Magnetizations of pure Ni, 10 at% Cu–Ni, 10 at% Co–Ni, 46 at% Fe–Ni and amorphous 16 at% B–Fe alloys have been measured in static magnetic fields up to 100 kOe in the temperature range around the Curie points. The relation between magnetization M , field H and temperature T is satisfactorily fitted to an equation ( H / M ) 0.75 = a ( T - T c )+ b M 2.5 for all the alloys investigated, where a and b are constant parameters and T c is the Curie temperature. Accordingly, isotherms of the Arrott-Noakes plots, M 2.5 vs ( H / M ) 0.75 , are parallel straight lines.

Journal ArticleDOI
TL;DR: The magnetic domain structure of gadolinium has been studied over the temperature range 230 K to 293 K as discussed by the authors, where the two magnetic phase transitions that exist in the magnetization were observed at the Curie temperature, 291 K and the change in the easy direction of magnetization at 240 K.

Journal ArticleDOI
TL;DR: Amorphous Fe-La alloys prepared by high-rate sputtering are ferromagnetic as mentioned in this paper, and the saturation magnetic moment vs. composition curve has a maximum around 75 at% Fe, while the Curie temperature decreases gradually with increasing Fe concentration.

Journal ArticleDOI
TL;DR: The magnetocrystalline anisotropy constants K 0 2 and K 0para 2 were determined from the analyses of the magnetization curves at 4.2 K and anisotropic paramagnetic Curie temperature, respectively as mentioned in this paper.
Abstract: Measurements of the magnetization and the magnetic susceptibility have been made along the principal axes of Tb–Sm single crystals. The alloys exhibit a ferromagnetic structure at low temperatures in the composition region up to 50 at% Sm and screw-antiferromagnetism appears in the sequence of increase of temperature in the compositions less than about 10 at% Sm. In Sm-rich alloys, the magnetic structure is presumably a Sm-type which has two magnetic transition temperatures T N1 and T N2 . The temperature difference between T N1 and T N2 decreases with decreasing Sm concentration. The magnetocrystalline anisotropy constants K 0 2 and K 0para 2 were determined from the analyses of the magnetization curves at 4.2 K and anisotropic paramagnetic Curie temperature, respectively.

01 Jan 1980
TL;DR: In this paper, the indirect exchange interaction between two localized moments, wHx&h Xarises from the virtual transi- tions between the filled valence band and the empty conduction band (Bloembergen and Rowland mechanism) was investigated in Hg^^MnxTe and Cd-, Kn Te alloys.
Abstract: We investigate in Hg^^MnxTe and Cd-, Kn Te alloys, the indirect exchange interaction between two localized moments, wHx&h Xarises from the virtual transi­ tions between the filled valence band and the empty conduction band (Bloembergen and Rowland mechanism) . Both cases of zerogap materials (Hg-^xMnxTe alloys of low x) and semiconducting materials (Hgx-xMnxTe alloys of large x and Cdi-xMnxTe alloys) are examined. The Curie Weiss temperature is calculated and compared to the avai­ lable experimental results.


Journal ArticleDOI
TL;DR: In this article, both stoichiometric and non-stochastic BaVS3 has been studied and the results are discussed in the context of present models for this pseudo-one-dimensional material.