Showing papers on "Curie–Weiss law published in 1970"
102 citations
TL;DR: In this paper, the magnetic properties of manganese compounds with C1 b -type crystal structure are studied and a conclusion that the concentration of conduction electrons is very important in determining the magnetic interaction is made.
Abstract: Magnetic properties of manganese compounds with C1 b -type crystal structure are studied. CuMnSb (lattice parameter a =6.09 5 A) is antiferromagnetic with a Neel temperature of 55°K and an asymptotic Curie temperature of -160°K. The paramagnetic Bohr magneton number per Mn is 5.4 7 . PdMnSb ( a =6.24 6 A) is ferromagnetic with a Curie temperature of 500°K and the magnetic moment per Mn is 3.9 5 µ B . Magnetic studies are also carried out for the compounds in which Ni or Pd are substituted for Cu in CuMnSb, resulting in a conclusion that the concentration of conduction electrons is very important in determining the magnetic interaction. Qualitative interpretation of experimental results is given based on the theory of resonance scattering by Friedel, Caroli and Blandin.
57 citations
TL;DR: In this paper, the static magnetic susceptibilities of simplified model vibronic systems where non-Kramers paramagnetic ions in triplet ground state interact either with localized tetragonal modes of vibration with sharp frequency spectrum at ω (localized model), or with TRSs composed of the superposition of phonons with continuous frequency spectrum (Debye model) are calculated in a rigorous way.
Abstract: Static magnetic susceptibilities of simplified model vibronic systems where non-Kramers paramagnetic ions in triplet ground state interact either with localized tetragonal modes of vibration with sharp frequency spectrum at ω (localized model), or with tetragonal modes composed of the superposition of phonons with continuous frequency spectrum (Debye model) are calculated in a rigorous way. The susceptibility is simply expressed in terms of a temperature dependent reduction factor γ L ( T ) for the localized model, or γ D ( T ) for the Debye model, which diminishes the effective Curie constant and makes the susceptibility deviate from the Curie-Weiss law. The theory explains the characteristic features of the susceptibilities of dilute solid solutions of UO 2 in ThO 2 measured by Slowinski and Elliott and by Comly, for example, the convex curvature of reciprocal susceptibility vs. temperature plot. The values of parameters determined to fit the observed susceptibilities are reasonable in orders of magnitude.
40 citations
38 citations
TL;DR: Magnetic and structural characteristics of ternary intermetallic systems with lanthanides, considering Ln substitution by other rare earth elements are discussed in this paper, where the authors consider the case where lanthanide substitution is considered.
Abstract: Magnetic and structural characteristics of ternary intermetallic systems with lanthanides, considering Ln substitution by other rare earth elements
38 citations
TL;DR: In this paper, the magnetic properties of the cubic RCu5 compounds TbCu5, DyCu5 and TmCu5 are reported for temperatures between 2.1° and 300°K.
Abstract: The magnetic properties of the cubic RCu5 compounds TbCu5, DyCu5, HoCu5, ErCu5, and TmCu5 are reported for temperatures between 2.1° and 300°K. In the paramagnetic region the susceptibility follows a Curie‐Weiss law. The type of ordering at low temperatures changes with increasing atomic number from antiferromagnetic (R = Tb) to ferromagnetic (R = Ho, Er, Tm), while DyCu5 is metamagnetic. The Knight shifts of the 63Cu NMR in these compounds have been measured between 100° and 300°K. The results are discussed in terms of the Ruderman‐Kittel‐Kasuya‐Yosida theory.
35 citations
TL;DR: In this article, the electrical resistivity of single crystal Fe1.91P was measured from 80 to 360°K, and a break in the resistivity curve occurred at 220°K and coincided with the abrupt change in the magnetization curve.
34 citations
29 citations
TL;DR: In this article, the magnetic properties and the electrical resistivity, the Hall effect, the thermoelectric power, and the magnetoresistance were carried out on polycrystalline rhombohedral Cr2S3.
25 citations
TL;DR: The magnetic susceptibility of LiFePO4 and LiCoPO4 has been measured as mentioned in this paper, and the results, when interpreted on a simple molecular field theory, explain why antiferromagnetic resonance at millimeter wavelengths was not observed with magnetic fields of up to 50 kG.
25 citations
TL;DR: In this article, the number of Bohr magnetons per elementary cell is estimated by fitting the curve of the saturation magnetization σ versus temperature, and the cation distribution over the available lattice sites has been deduced.
Abstract: Mossbauer measurements were carried out in compound BaMg 2 Fe 16 O 27 (Mg 2 W) by utilizing both polycrystalline and single-crystal samples. The resonant γ-absorption spectra have been measured with the absorbers at temperatures of 85 to 800°K and in some cases in the presence of a 15-kOe external magnetic field. The values of the hyperfine magnetic fields H hf at the Fe57nuclei in the different sublattices as functions of temperature have been measured. By fitting the curve of the saturation magnetization σ versus temperature, the cation distribution over the available lattice sites has been deduced. From the value of σ extrapolated at 0°K, it turns out that the number of Bohr magnetons (n_{B})W per elementary cell is higher than the value obtained by adding the corresponding values for the S and M structures. The Curie temperature of the compounds has also been measured and is equal to (440 ± 5)°C.
TL;DR: In this paper, the homogeneous composition range and magnetic properties of the hexagonal Laves-Phase compound, CO 2+ x Ti 1-x (x > 0), have been determined by X-ray diffraction and magnetic studies.
Abstract: The homogeneous composition range and magnetic properties of the hexagonal Laves-Phase compound, CO 2+ x Ti 1- x ( x >0), have been determined by X-ray diffraction and magnetic studies. X-ray diffraction studies show that the MgNi 2 -type structure is stable in a narrow composition range from about 29 to 31.3 at.% Ti at room temperature. Magnetic measurements made at temperatures from 4.2° to 1,000°K indicate that these MgNi 2 phase compounds are ferromagnetic with Curie points lower than 44°K, showing a conspicuous concave toward the temperature axis in every reciprocal magnetic susceptibility vs. temperature curve about the Curie point. It is shown that magnetic data can be interpreted under the assumption that excess cobalt atoms behave as impurity atoms with a localized moment located in the matrix of a paramagnetic compound, similarly to the case of the analysis of the magnetism of dilute magnetic alloys.
TL;DR: The magnetizations of several PdFe alloys containing 0.05-0.15 at.% iron have been measured as functions of field (0.06-18.5 kG) and temperature (1.2-4.2 degrees K) as discussed by the authors.
Abstract: The magnetizations of several PdFe alloys containing 0.05-0.15 at.% iron have been measured as functions of field (0.06-18.5 kG) and temperature (1.2-4.2 degrees K). The results are interpreted by assuming that the magnetizations for each alloy may be separated into contributions from the palladium matrix and 'giant' moments associated with the iron atoms. The latter show paramagnetic behaviour which can be represented by Brillouin functions with arguments incorporating an internal field proportional to the magnetization. The saturation magnetizations indicate that a moment of 9 Bohr magnetons is associated with each iron atom and the form of the Brillouin functions suggest that complexes of iron atoms are formed carrying considerably larger magnetic moments. The 0.15 at.% alloy was found to be ferromagnetic with a Curie temperature of 2.1+or-0.05 degrees K.
TL;DR: Magnetic and transport measurements in ferromagnetic EuB6 show evidence for a Fisher-Langer-type resistance anomaly near Tc, and they may not be a simple ferromagnet, and the magnetic coupling might be influenced by a temperaturedependent conduction electron concentration as mentioned in this paper.
Abstract: Magnetic and transport measurements in ferromagnetic EuB6 show (a) evidence for a Fisher‐Langer‐type resistance anomaly near Tc, (b) that EuB6 may not be a simple ferromagnet, and (c) that the magnetic coupling might be influenced by a temperature‐dependent conduction electron concentration.
TL;DR: In this article, the magnetic properties of a series of ferromagnetic alloys of ZrZn2−x, where x varies from 0.05 to 0.2, were studied.
Abstract: We have studied the magnetic properties of a series of ferromagnetic alloys of ZrZn2−x, where x varies from 0.05 to 0.2. We found that the Stoner theory of ferromagnetism was consistent with the data taken below Tc for all samples. Above Tc, however, the susceptibilities obeyed Curie‐Weiss laws, χ∝[1−(T/Tc)]−1, and not χ∝[1−(T2/Tc2)]−1, as expected from the Stoner theory.
TL;DR: In this paper, a phase diagram with the corresponding magnetic properties for the Pr-Gd system was found, covering the whole range of compositions, and the magnetization measurements were made in fields extending to 26 KOe in the temperature range 2°-500°K.
Abstract: Various Pr–Gd alloys, covering the whole range of compositions, have been studied by x‐ray diffraction and static magnetic measurements. The magnetization measurements were made in fields extending to 26 KOe in the temperature range 2°–500°K. For the Pr–Gd system, we find the following phase diagram with the corresponding magnetic properties: (1) a Pr‐rich phase of double hexagonal structure which is paramagnetic down to 2°K and which follows the Curie‐Weiss Law; (2) A Gd‐rich phase of compact hexagonal structure which is ferromagnetic at low temperature; and (3) A phase based on the composition Pr2Gd5 of super hexagonal structure (analogous to the structure of Sm) which is antiferromagnetic at low temperature. Two alloys having compositions just either side of this superhexagonal phase were studied. Their crystallographic structures could not be determined with precision. Their magnetic behavior corresponds to that observed in ferrimagnets. The ferromagnetic Curie temperatures of these alloys are higher ...
TL;DR: The magneto-photoconductivity of EuO near the Curie temperature T c has been studied as a function of temperature and of magnetic field by using a fast-pulse technique in order to obtain clearer information on the transport properties of ferromagnetic semiconductors as mentioned in this paper.
TL;DR: In this article, the behavior of carriers trapped around doped Ti ions in VO 2 was investigated by means of the electron spin resonance in a temperature range between liquid nitrogen and room temperature, and the line shapes were examined for different concentration of Ti.
Abstract: The behavior of carriers trapped around doped Ti ions in VO 2 is investigated by means of the electron spin resonance in a temperature range between liquid nitrogen and room temperature. The line shapes are examined for different concentration of Ti. At lower concentration well resolved hyperfine lines are observed and a broad background line is superposed to them. With increasing impurity concentration, however, the single broad line grows up and the hfs lines diminish. At higher concentration only a single broad line of the Lorentz type is observed. The temperature dependences of the linewidth and the intensity for the hfs and broad lines are measured. The width of the broad line which does not vary at low temperature starts to increase at a temperature above which the intensity deviates from the Curie law. The motion of carriers localized around Ti impurity centers is discussed from these results.
TL;DR: Abrikosov's technique in the treatment of s-d problem was developed for the calculation of the dressed Curie constant of a magnetic impurity in metals as mentioned in this paper, which is used in this paper.
TL;DR: The molar susceptibility of Ce x Th1−x (x = 0.261, and 0.664) exhibits a Curie law behavior above 300°K, decreases with decreasing temperature between 300 and 60°K.
TL;DR: In this article, the magnetic field controlling Curie point switching is on the order of 30 O(n −Bi films can be prepared such that the Magnetic Field Controlled Curie Point Switching (MFCS) can be achieved.
Abstract: Mn–Bi films can be prepared such that the magnetic field controlling Curie‐point switching is on the order of 30 Oe.
TL;DR: In this article, the results of hyperfine magnetic field measurements on the ferromagnetic phase of dilute (~ 1 at.%) alloys of iron in Pd or Rh-Pd host matrices have yielded values for Curie temperatures and spins associated with local moments.
Abstract: Hyperfine magnetic field measurements on the ferromagnetic phase of dilute (~ 1 at.%) alloys of iron in Pd or Rh-Pd host matrices have yielded values for Curie temperatures and spins associated with local moments. From the line broadening effects observed in the Mossbauer spectra, values have been found for the range of the exchange field distribution surrounding each iron atom. This is found to be a function of matrix susceptibility. The variation of hyperfine field with H/T (where H is a constant applied field and T a variable temperature) for the alloys can be described in terms of a molecular field model only if values of Curie temperature are assumed which are greater than those directly measured. These higher values are consistent with the results of magnetization measurements for Curie temperatures in dilute Fe-Pd alloys
TL;DR: Combined recoilless γ-resonance and magnetization measurements indicate the existence of critical spin fluctuations and of critical superparamagnetism in EuO as mentioned in this paper.
TL;DR: In this paper, a relation between three critical parameters is established which determine the field dependence of the longitudinal magnetization and the Curie temperature, and the temperature-dependence of the magnetization.