Showing papers on "Curie–Weiss law published in 1984"
TL;DR: In this paper, single-phase LaNi1-xMnxO3 samples in the compositional range 0 0.05 to 0.50 K were used to investigate the ferromagnetic spin glass properties of LaNi 1-mnx oxide.
Abstract: Single-phase LaNi1-xMnxO3 samples in the compositional range 0 0.05, but any motional enthalpy appears to remain small ( Delta Hm approximately=0). The x=0.1 sample exhibits ferrimagnetic spin glass behaviour below 40K, and the ferromagnetic interactions increase with manganese concentration. The oxide with x=0.50 is ferromagnetic with a well defined Curie temperature.
70 citations
TL;DR: In this paper, the same authors investigated the optical Faraday rotation in the temperature range 8-300 K at 0.6328 μm wavelength in a magnetic field up to 20 kOe.
Abstract: On three fluorides CeF3, NdF3, and PrF3 accurate susceptibilities measurements are reported from 2 up to 300 K under a magnetic field applied along the c axis. On the same samples, the optical Faraday rotation has been investigated in the temperature range 8–300 K at 0.6328 μm wavelength in a magnetic field up to 20 kOe. The reciprocal susceptibilities χ−1(T) follow a Curie Weiss law for T>100 K; the observed values of the paramagnetic Curie temperature are − 56 K (PrF3), − 114 K (CeF3), and − 26 K (NdF3). For T 77 K. (V and χ are expressed in deg cm−1 Oe−1 and in μB mol−1 Oe−1, respectively.) On one hand for NdF3 and PrF3, it ...
59 citations
TL;DR: In this article, the magnetization of the itinerant electron ferromagnetic Ni 3 Al system has been measured and the experimental result of temperature dependence of the spontaneous magnetization agrees with the prediction of the self-consistent renormalization (SCR) theory of spin fluctuations.
Abstract: The magnetization of the itinerant electron ferromagnetic Ni 3 Al system has been measured. The experimental result of temperature dependence of the spontaneous magnetization agrees with the prediction of the self-consistent renormalization (SCR) theory of spin fluctuations. Considering the variations of the band structures with the Ni-concentration x by alloying, the experimental result of the x -dependence of the Curie temperature T c is also explained within the framework of the SCR theory.
42 citations
TL;DR: In this paper, it was found that the Curie-Weiss law should widely be applied for the high field diamagnetic susceptibility of organic liquids consisted of anisotropic diamagetic molecules.
Abstract: High field diamagnetic susceptibility of organic liquids is measured by means of linear magnetic birefringence (Cotton-Mouton effect) in pulsed high magnetic field up to 400 kOe with special interest in the temperature dependence. It is found that the “Curie-Weiss law” should widely be applied for the high field diamagnetic susceptibility of organic liquids consisted of anisotropic diamagetic molecules. The “Curie-Weiss constant” \(\varTheta\) reflects the intermolecular correlation in liquids and the obtained values are 0, 145 and 165 K for benzene, chlorobenzene and nitrobenzene, respectively.
32 citations
TL;DR: In this article, the analysis of the paramagnetic susceptibility of a substance by means of a modified Curie-Weiss law is discussed, and it is shown that the experimental parameters x ∗o and C ∗ should be renormalized in order to obtain physical quantities directly related to the crystal field groud state properties.
32 citations
TL;DR: In this paper, the d.c. magnetization of Mo/Ni artificial superlattices in the temperature range 5-300 K and in magnetic fields of up to 10 7 /4 π Am -1 (10kG) was studied.
26 citations
24 citations
TL;DR: In this paper, single crystals of neodymium bromate were grown and their principal magnetic susceptibility and anisotropy determined from 90 to 300 K. The results were analyzed with one electron crystal field (CF) with the intermediate coupling reduced matrix elements.
Abstract: Single crystals of neodymium bromate were grown and their principal magnetic susceptibility and anisotropy determined from 90 to 300K. The anisotropy, which is relatively small, decreases with lowering of temperature and suffers a reversal at ∼155 K. The magnetic moment peff shows a small linear variation with temperature. A least squares fit yields Curie constant C=1.666 and paramagnetic Curie temperature θ=−23.76 K for χ. The results were analyzed with one electron crystal field (CF) with the intermediate coupling reduced matrix elements. Inclusion of J mixing through the CF with all the 4I J manifolds leads to a considerable change in the Stark energies and the magnetic properties. A theoretical analysis of the observed optical absorption and magnetic data shows conclusively that the next nearest neighbor interactions which reduce the Nd3+ site symmetry to C3v do have a significant role to play. The effects of the CF on the thermal and hyperfine behavior of Nd3+ in bromate lattice have been worked out...
23 citations
TL;DR: In this article, the exact expression for the Curie temperature of a spin-1 Bethe lattice with dipolar and quadrupolar interactions was derived and the nature of variation of the temperature with quad-rupolar interaction constant was studied.
22 citations
TL;DR: In this article, an improved method of calculating the vector exchange field in an itinerant electron magnet, which may vary in both magnitude and direction from atom to atom, is presented, which involves the use of the couple acting on the magnetic moments on the atoms in their surrounding exchange field.
Abstract: A new, improved method of calculating the vector exchange field in an itinerant electron magnet, which may vary in both magnitude and direction from atom to atom, is presented. This involves the use of the couple acting on the magnetic moments on the atoms in their surrounding exchange field. By studying the way in which the moments align with the field at each atomic site, the exchange field may be mapped out. Thus the method may be used to calculate the magnetic couplings between individual atomic moments in the system in some arbitrary magnetic configuration with any desired set of directions and magnitudes of exchange splitting. In this way it is possible, for instance, to model a disordered state above the Curie temperature. The authors how that their formula for the couple can be derived either from the equation of motion for the spin or from the total energy expression, and their present results obtained using the method for BCC ferromagnetic iron.
20 citations
TL;DR: In this paper, the effects of the D-term on the Curie temperature of the anisotropic Heisenberg ferromagnet with mixed spins S = 12 have been investigated and shown to be significant for D > 0.
TL;DR: The magnetization of Pb 1− x Mn x Te for samples with x = 0.01, 0.022, and 0.04 has been investigated at magnetic fields up to 40 kOe and over a temperature range from 2 to 25 K as mentioned in this paper.
TL;DR: In this paper, the Chevrel phase holmium molybdenum sulfide has been grown in sealed crucibles and a large range of Ho concentration was measured on crystals oriented with the hexagonal c axis parallel to the applied magnetic field in the temperature range 5 to 200 K using a SHE SQUID magnetometer and a force balance.
Abstract: Single crystals of the Chevrel phase holmium molybdenum sulfide of approximately 0.15 mm on edge have been grown in sealed molybdenum crucibles. On the bases of microprobe and full x‐ray structure analysis we find a large range of Ho concentration. Susceptibilities were measured on crystals oriented with the hexagonal c axis parallel to the applied magnetic field in the temperature range 5 to 200 K using a SHE SQUID magnetometer and a force balance. We observed a paramagnetic Curie Weiss behavior in this temperature interval with θ≊0 K and a molar Curie constant about a factor of 2 larger than the expected theoretical value of 14.1. The large value of CM suggests that the Ho spins are constrained by the crystal field to the c axis. The perpendicular susceptibility is extremely small. A superconducting transition at ∼2.4 K is measured in low fields by an ac SQUID technique.
TL;DR: The magnetization process of an itinerant-electron magnet Hf 0.8 Ta 0.2 Fe 2 has been measured in pulsed magnetic fields up to 300 kOe at 4-330 K as discussed by the authors.
TL;DR: In this paper, the Curie temperature of polycrystalline DyFe 3 has been determined in a magnetic field H = 10 kOe and the magnetic moment has been measured at 4.2 K. The mean domain with D is determined in its dependence on the grain size.
TL;DR: In this paper, the forced volume magnetostriction measured precisely in a relatively weak magnetic field shows a sharp maximum in the region of Curie temperature for a 36.4 at%Ni-Fe Invar alloy.
Abstract: The forced volume magnetostriction measured precisely in a relatively weak magnetic field shows a sharp maximum in the region of Curie temperature for a 36.4 at%Ni-Fe Invar alloy. The magnetovolume coupling constant C determined in the temperature range between room temperature and the Curie temperature is found to be approximately 1.2 ×10 -8 cm 6 /emu 2 and almost independent of the temperature, under the condition that the forced volume magnetostriction is related with the local magnetic moment and the high-field susceptibility due to the band term.
TL;DR: In this article, the magnetic susceptibility of 1T-TaS 2 was measured at low temperatures, with the paramagnetic Curie point of 1.5 K in the measured temperature range of 10 K to 40 K.
Abstract: Magnetization of 1T-TaS 2 single crystal in the Anderson localized state has been measured at low temperatures. The magnetic susceptibility of 1T-TaS 2 follows the Curie-Weiss law with the paramagnetic Curie point of 1.5 K in the measured temperature range of 10 K to 40 K. Forromagnetic order was found at ca. 0.9 K.
TL;DR: In this paper, the dc and ac susceptibility and high-field magnetization on disordered samples of MnPd3 and CrPd4 were investigated. But the data were discussed in terms of a cluster-glass model with local antiferromagnetic interactions.
Abstract: We report studies of dc and ac susceptibility and high‐field magnetization on disordered samples of MnPd3 and CrPd3. Both samples undergo spin‐glass‐like transitions, as is evident from susceptibility peaks at 45 and 37 K, respectively. The effective paramagnetic moments deduced from Curie–Weiss fits of the susceptibility in the paramagnetic region are 0.38μB/Mn and 0.4μB/Cr. Both materials show saturation effects at high applied fields and a flat χ(T) below the spin‐freezing temperature in the field‐cooled state. The data are discussed in terms of a cluster‐glass model with local antiferromagnetic interactions.
TL;DR: The bulk magnetic properties of the series of polycrystalline compounds RAgGa (where R is Pr, Nd, Gd, Tb, Dy, Ho, Er, or Tm) have been determined in applied fields up to 26 kOe and temperatures from 3 to 300 K as mentioned in this paper.
Abstract: The bulk magnetic characteristics of the series of polycrystalline compounds RAgGa (where R is Pr, Nd, Gd, Tb, Dy, Ho, Er, or Tm) have been determined in applied fields up to 26 kOe and temperatures from 3 to 300 K. These compounds form with the body‐centered orthorhombic crystal structure of the CeCu2 type. At high temperatures their reciprocal susceptibilities follow Curie–Weiss type behavior; their effective paramagnetic moments are in reasonable agreement with those calculated for the appropriate tripositive rare‐earth ion; their asymptotic Curie temperatures are all relatively small and positive. At low temperatures, the Gd, Ho, and Er compounds order ferromagnetically; the Tb compound orders antiferromagnetically; the Dy compound is metamagnetic; the Pr and Tm compounds almost order ferromagnetically at the lowest measured temperature.
TL;DR: In this paper, the temperature dependence of magnetization and magnetic susceptibility and hydrostatic pressure effect on the Surie temperature (d T c /d P ) are measured for (Co 1- x Mn x ) 2 B (0⪯ x ⪯0.4) amorphous alloys and the results are compared with those of crystalline compounds with the same composition.
TL;DR: In this paper, a localized canting model has been extended and used to compute 0°K magnetic moments and Curie temperatures of substituted lithium ferrites with substitution levels up toz=0·7.
Abstract: Because of their several attractive features including relatively high Curie temperatures, substituted lithium ferrites have become important for applications at microwave frequencies. Neel collinear arrangement of spins onA andB sublattices is unable to satisfactorily explain the 0°K saturation moments and the observed Curie temperatures of the zinc-substituted lithium ferrites, especially at concentrations of zincz>0·3 in the formula Li0·5−z/2ZnzFe2·5−z/2O4. Rosencaig’s localized canting model has been extended and used to compute 0°K magnetic moments and Curie temperatures of these ferrites with substitution levels up toz=0·7. Reasonably good agreement between the calculated and experimental values, both for the 0°K magnetic moments and the Curie temperatures, has been obtained using exchange parameters ratios based on the valuesJaa=−20°K,Jbb=−8°K andJab=Jba=−29°K.
TL;DR: In this article, optical microscope observations have been made of magnetic domains in single crystals of EuxSr1−xS with the nominal value of x=1.0, 0.70, and 0.54.
Abstract: Optical microscope observations have been made of magnetic domains in single crystals of EuxSr1−xS with the nominal value of x=1.0, 0.70, 0.54. No magnetization structure was seen for several lower values of x. Susceptibility measurements in the Curie–Weiss law regime and electron microprobe measurements were used to characterize the individual samples. The abrupt onset of visible magnetization structure on cooling provides a sensitive measure of TC. In striking contrast, on further cooling of a reentrant composition the contrast fades very slowly. Thus the change from ferromagnet to spin glass is spread over several tenths of a degree Kelvin. All of the crystals contain thin plate‐like inclusions of a second Eu rich phase which represents less than about 0.1% of the volume. The observed domains differ considerably with Eu concentration. The salient characteristics may be summarized for nominal x=1.0: polygonal domains with M largely normal to the (100) sample plane; typical dimensions, 3–25 μm; x=0.7: ma...
TL;DR: In this article, the Curie-Weiss contribution was analyzed for the solid solutions of Ti/SUB 1-x/ V /SUB x/ PO/sub 4/ under the reductive circumstance, although there seems to be immiscibility near x=0.5.
TL;DR: A phenomenological expression for the susceptibility form the Curie temperature to infinite temperature, developed from the Heisenberg model of magnetism, was given in this article, applied here to the ferromagnetic metals iron and nickel.
TL;DR: In this article, the role of the electron-phonon interaction (EPI) in the magnetism of a metal was investigated and it was shown that EPI can affect the spontaneous magnetization as much as ∼ 1μB per atom.
Abstract: Starting from a consideration on how the phonon frequency and, therefore, the phonon free energy change with the spin splitting of the electron bands, we show how important a role the electron‐phonon interaction (EPI) plays in the magnetism of a metal. In the paramagnetic state we find EPI to be the dominant mechanism of the temperature dependence of the spin susceptibility of a metal. Among others, the Curie‐Weiss behavior is quite naturally obtained for an itinerant electron ferromagnet, without requiring the presence of localized moments. In the ferromagnetic state of a metal we find that EPI can affect the spontaneous magnetization as much as ∼ 1μB per atom.
TL;DR: The thermal dependence of electron paramagnetic resonance spectra of neutron irradiated GaAs is studied in this paper, showing that the ASGa quadruplet and the intensity correlated singlet display a similar deviation from the Curie law above 100 K, indicating that both former centers are likely associated in a complex of intrinsic nature.
Abstract: The thermal dependence of electron paramagnetic resonance spectra of neutron irradiated GaAs shows that the ASGa quadruplet and the intensity correlated singlet display a similar deviation from the Curie law above 100 K, indicating that both former centers are likely associated in a same complex of intrinsic nature.
TL;DR: In this article, the intensity of beta particles transmitted through thick targets of barium titanate and triglycene sulphate shows an anomalous decrease at the Curie temperature indicating a new mode of energy loss of electrons in ferroelectrics at the curie temperature.
TL;DR: In this paper, the authors analyzed the stability of configurations with various degrees of magnetic order, i.e., from the perfect ferromagnet to the paramagnetic disordered moment state.
Abstract: The range of validity of the simple alloy model for magnetism in transition metals is studied. By assuming that the local magnetic moments point up or down along a given direction, we analyzed the stability of configurations with various degrees of magnetic order, i.e., from the perfect ferromagnet to the paramagnetic disordered moment state. The electronic structure is solved within the coherent-potential approximation and for two different model density of states. In particular, results are presented for the behavior of the magnetic moments, the magnetic phase diagram, and the Curie temperature. The shortcomings of the alloy model are discussed by comparison with Hubbard's recent theory of magnetism. It is shown how to extend the simple-alloy-model theory to include the important magnetic moment fluctuations taken into account by Hubbard.