Showing papers on "Curie–Weiss law published in 1977"
TL;DR: In this paper, the magnetic properties of hexagonal Fe 2 P single crystal are studied by the measurements of magnetization, susceptibility, thermal expansion and electrical resistivity along the principal crystallographic axes.
Abstract: The magnetic properties of hexagonal Fe 2 P single crystal are studied by the measurements of magnetization, susceptibility, thermal expansion and electrical resistivity along the principal crystallographic axes. It is found that the saturation magnetization per molecule and the Curie temperature are 2.94 µ B and 208.6 K, respectively, and the anisotropy constant K 1 is 2.32×10 7 erg/cm 3 at 4.2 K, which is considerably larger than the values in 3d-transition compounds. The thermal expansion and the electrical resistivity show discontinuous changes at the Curie temperature indicating that the ferromagnetic to paramagnetic transition of Fe 2 P is accompanied by the first-order transition due to magnetoelastic effects. The exchange striction obtained from the measurement of thermal expansion is discussed on the basis of the theory of Bean and Rodbell.
120 citations
TL;DR: In this article, the magnetic moment per transition metal atom at 0°K and the Curie temperature were obtained for a series of (Fe, Ni) 80 (P, B) 20 amorphous quenched alloy ribbons.
Abstract: The magnetic moment per transition metal atom at 0°K and the Curie temperature were obtained for a series of (Fe, Ni) 80 (P, B) 20 amorphous quenched alloy ribbons. Fe/Ni and P/B compositions were varied separately. The moment data can be fitted well by assigning 2.1 Bohr magnetons per Fe atom and 0.6 per Ni atom, with the moment being lowered by 0.3 per B atom and 1.0 per P atom. Alternatively, moments varying with composition, as shown by neutron diffraction in crystalline alloys, combined with a lowering of 1.2 per B atom and 2.1 per P atom, also fit well. For a given P/B composition, T c shows a broad maximum at Fe:Ni of about 3:1. For a given transition metal composition, T c increases with increasing B content.
82 citations
74 citations
TL;DR: In this paper, different classes of disordered magnetic systems (spin glass systems, crystalline magnetic alloys, and amorphous ferro-and ferrimagnets) are characterized and delimited with respect to each other.
36 citations
33 citations
TL;DR: Saturation magnetic moments (4.2 K), room-temperature magnetizations, and some Curie temperatures were reported for several TM80P20 metallic glasses (TM=Fe, Co, and Ni) as mentioned in this paper.
Abstract: Saturation magnetic moments (4.2 K), room‐temperature magnetizations, and some Curie temperatures are reported for several TM80P20 metallic glasses (TM=Fe, Co, and Ni). These data complement previously published results for TM80B20 glasses and confirm the model in which approximately 2.4 and 1.6 electrons/metalloid atom are transferred by P and B, respectively, to TM d states.
31 citations
TL;DR: In this article, the initial susceptibility and magnetization as a function of applied field and temperatures have been measured for the amorphous alloys RE 50 Ag 50 (RE=Gd, Tb, Dy, Ho, and Er).
Abstract: The initial susceptibility and magnetization as a function of applied field and temperatures have been measured for the amorphous alloys RE 50 Ag 50 (RE=Gd, Tb, Dy, Ho, and Er). These have been supplemented by measurement of the time dependence of magnetization. All these alloys exhibit a spontaneous magnetization at low temperatures. An order of magnitude for the magnetic anisotropy has been determined from the experimental data. The diverse phenomena responsible for magnetic ordering and the magnetic after-effect are analysed and discussed.
30 citations
TL;DR: In this article, the magnetic susceptibility of Bi 1−x Sb x alloys is investigated for the concentration range 0 ⩽x≲22 at%, the temperature range 4.2 −270 K, and magnetic fields up to 60 kOe.
Abstract: The magnetic susceptibility of Bi 1−x Sb x alloys is investigated for the concentration range 0 ⩽x≲22 at%, the temperature range 4.2–270 K, and magnetic fields up to 60 kOe. The experimental results are compared with the theoretical dependences of susceptibility on the band parameters, temperature, and magnetic field.
27 citations
TL;DR: In this article, the χ(T) curves for 17 binary and 2 ternary ytterbium intermetallics have been found to have a common functional form with a characteristic temperature Tmax.
Abstract: Out of 17 binary and 2 ternary ytterbium intermetallics, in the five systems, YbGa2, YbCu2, YbAl2, YbAl3 and YbCuAl an intermediate valency was found. The χ(T) curves for these compounds have a common functional form with a characteristic temperature Tmax. No tendency to saturation is observed in the magnetization at 1.4 K in fields up to 330 kOe.
26 citations
TL;DR: In this paper, the effect of the melt PbO/B 2 O 3 ratio on the Curie temperature of LPE films containing lutetium is described along with data showing the flux effect on the bubble collapse field temperature dependence.
Abstract: The effect of the melt PbO/B 2 O 3 ratio on the Curie temperature of LPE films containing lutetium is described along with data showing the flux effect on the bubble collapse field temperature dependence. A mechanism is proposed to explain the observed data involving the complexing of the rare-earth ions in the melt by B 2 O 3 . A correlation is shown between the Curie temperature and lattice parameter of lutetium containing LPE films where certain of the important melt ratios are held constant. The variation of Curie temperature with changing growth temperature is also described. The previously observed Curie temperature dependence on the Fe 2 O 3 /Lu 2 O 3 ratio is confirmed over a wider range of iron to lutetium ratios. The effect of changing the PbO/B 2 O 3 ratio and its effect on flux removal is presented.
25 citations
TL;DR: In this paper, the formation of the magnetic moment of the Co atom was investigated in the pseudobinary alloys CoTi1-xAlx by X-ray diffraction, magnetic measurement and NMR of 59Co.
Abstract: The formation of the magnetic moment of the Co atom is investigated in the pseudobinary alloys CoTi1-xAlx by X-ray diffraction, magnetic measurement and NMR of 59Co. Magnetization and Curie temperature have a maximum at the composition less than x=0.5, where the alloy becomes one of the well known ferromagnetic Heusler alloys. The results are discussed on the basis of a local environment model. The moment of the Co atom appears when the atom is surrounded with four, five and six Ti atoms at nearest-neighbour distance.
TL;DR: On the splat-cooled metallic (Fe.79 Si.21 ) 1-x B x. glasses, concentration dependence of the magnetic properties has been investigated in this article, where magnetic domain structures have been observed.
Abstract: On the splat-cooled metallic (Fe .79 Si .21 ) 1-x B x . glasses the concentration dependence of the magnetic properties has been investigated. For representative specimens, magnetic domain structures have been observed. The crystallization temperature increases and the Curie temperature monotonously decreases from 713 K to 671 K contrary to the result for reported Fe-P-C or Fe-P-B glasses as the metalloid content is increased. The highest value of crystallization temperature (797 K) is about 150 K higher than those for iron-rich glassy alloys reported up to now. The coercive force also depends on the boron content and the lowest value (0.04 Oe) has been obtained at about X=0.10. The magnetization process is discussed in the light of domain patterns observed.
TL;DR: The susceptibility of solid 3He was deduced from multiple echoes observed in pulsed NMR experiments as mentioned in this paper, and it follows a Curie Weiss law at high temperature, increases faster than this law below 5 mK and drops abruptly around 1 mK.
TL;DR: In this paper, Curie Weiss like laws are observed in γ-ray irradiated and low quality (SN) x crystals which show the resistivity minimum at 30-40 K.
TL;DR: In this paper, the anisotropy in the ordered region is discussed on the basis of an equal distribution of antiferromagnetic domains with spin direction along any of the three 〈100〉 axes.
Abstract: The susceptibility of a single crystal of antiferromagnetic uranium mononitride (TN ≃ 53 K) is reported between 4 and 1000 K. The paramagnetic susceptibility follows a modified Curie-Weiss law with a temperature-independent susceptibility χ0=8.0×10−6 emu cm−3 added, ϑ=−247 K, and 2.66 Bohr magnetons/U atom. Nearest and next nearest neighbor exchange constants are evaluated. The anisotropy in the ordered region is discussed on the basis of an equal distribution of antiferromagnetic domains with spin direction along any of the three 〈100〉 axes. Such an assumption is corroborated by thermal expansion measurements along the three 〈100〉 axes.
TL;DR: In this paper, it was shown that, near a surface, a high-density sheet of liquid3He between the first solid layer and the bulk paramagnetic liquid at zero pressure would behave as a two-dimensional itinerant ferromagnet.
Abstract: Arguments are given to show that, near a surface, a high-density sheet of liquid3He between the first solid layer and the bulk paramagnetic liquid at zero pressure would behave as a two-dimensional itinerant ferromagnet. Such a picture could explain recent experiments on the magnetic properties of3He in confined geometries in the 1 mK temperature range.
TL;DR: In this article, the magnetic influence on the conduction electron scattering was determined by comparing the resistivity of these compounds with the results for the nonmagnetic La 3− x S 4.
TL;DR: In this article, the forced volume magnetostriction, the volume dependence of the moment at 0'°K, the effective exchange energy, and the Curie temperatures of the amorphous materials were derived.
Abstract: Measurements have been made of hydrostatic pressure dependence (up to 4 kbar) of the ’’saturation’’ magnetization and Curie temperatures of some commercially available Fe‐Ni‐based metallic glass materials. The magnetizations decrease by a few tenths of a percent per kbar in the amorphous state and increase by about 1% per kbar in the crystalline form of the same material. The Curie temperatures of the amorphous materials decrease by a few tenths of a degree per kbar. From this work, it is possible to derive the forced volume magnetostriction, the volume dependence of the ’’saturation’’ moment at 0 °K, and the volume dependence of the effective exchange energy.
TL;DR: In this paper, the magnetization and the circular magnetic birefringence (CMB) or Faraday rotation φ F measurements in dysprosium iron garnet (DyIG) were reported in detail in the temperature range 2.6-300 K and under magnetic field H a up to 26 kOe applied along either the easy axis |111| or the intermediate |110| direction.
Abstract: The magnetization and the circular magnetic birefringence (CMB) or Faraday rotation φ F measurements in dysprosium iron garnet (DyIG) are reported in detail in the temperature range 2.6-300 K and under magnetic field H a up to 26 kOe applied along either the easy axis |111| or the intermediate |110| direction. Typical linear field dependences of the magnetization and CMB are observed and their spontaneous values are obtained by extrapolating these evolutions to zero applied field. It is shown that the use of single crystals avoids the treatment adopted for polycrystalline samples by Pauthenet who extrapolated to infinite fields which may be doubtful. The anisotropic character of the magnetic properties and of the Faraday rotation appears to be very important below 100°K. The rare-earth contribution to the total CMB is determined and the field dependence of the total Faraday rotation is discussed from the paramagnetic evolution of the Dy3+ions. Similar temperature evolutions are observed for the quantities χ-1and |\Delta\phi_{F}/\DeltaH_{a}|^{-1} where χ is the magnetic susceptibility. Our experimental data, corresponding to these quantities, show some disagreement from the free ion Curie-Weiss's law as observed previously in polycrystalline samples. New values for the paramagnetic Curie temperature and the molecular field parameters of the Dy3+sublattice are deduced from both the magnetic and magnetooptical data.
TL;DR: In this paper, the dielectric constant of RbHSO 4 along the ferroelectric axis has been measured for a well annealed specimen, and it has been shown that it obeys a Curie-Weiss law of e − e 0 = C /( T - T 0 ) in 0.06°C < T − T 0 <20°C with e 0 0 = 4.7, C =144 K and T 0 =-7.9°C in agreement with the Landau type mean field theory.
Abstract: Measurements of the dielectric constant of RbHSO 4 along the ferroelectric axis have been made for a well annealed specimen. The result indicates that, contrary to the previously reported results of the spontaneous polarization and the deuteron magnetic resonance in RbDSO 4 , the dielectric constant e obeys a Curie-Weiss law of e - e 0 = C /( T - T 0 ) in 0.06°C< T - T 0 <20°C with e 0 =4.7, C =144 K and T 0 =-7.9°C in agreement with the Landau type mean field theory.
TL;DR: In this paper, the magnetization of the one-dimensional random-bond Ising model with each bond energy either $+J$ or $\ensuremath{-}J$ with equal probability was obtained for various temperatures.
Abstract: The magnetization $m$ as a function of magnetic field $h$ for various temperatures is numerically obtained for the one-dimensional random-bond Ising model with each bond energy either $+J$ or $\ensuremath{-}J$ with equal probability. For high temperatures ($\frac{\mathrm{kT}}{J}g~0.6$) the results obtained agree with those of Landau and Blume. We have obtained $m$ vs $h$ for low temperatures as a numerical approach to the zero-temperature limit.
TL;DR: In this article, the hyperfine field H hf was found to be +16.6±0.1 kOe at 4.2 K and to decrease with increasing temperature in good agreement with the saturation magnetic moment, i.e. with the magnetic moment of cobalt atom, µ Co.
Abstract: NMR measurements for Co 59 in Co 2 TiAl below and above the Curie point 135 K were carried out. The hyperfine field H hf was found to be +16.6±0.1 kOe at 4.2 K and to decrease with increasing temperature in good agreement with the saturation magnetic moment, i.e. with the magnetic moment of cobalt atom, µ Co . At temperatures above 200 K, the Knight shift K changes linearly with respect to the susceptibility χ with a slope corresponding to +49.2±2 kOe/µ B . This value is in good agreement with the ratio H hf /µ Co in the ferromagnetic region.
TL;DR: In this paper, the Bethe-Peierls-Weiss method was employed to study the chemical disorder introduced by substituting magnetic impurities in a non-magnetic structurally disordered host.
Abstract: A classical Heisenberg ferromagnet with fluctuations in the nearest-neighbour exchange interaction is investigated by the Bethe-Peierls-Weiss method. The fluctuations, assumed to arise from the structural disorder, depress the values of the Curie temperature, the high-temperature magnetic susceptibility and the magnetization relative to the corresponding values for the average crystal. For small values of the fluctuation parameter, explicit expressions for the amount of decrease in the above quantities are obtained. The critical indices are, however, found to be unaffected by fluctuations. The same formalism is employed to study the chemical disorder introduced by substituting magnetic impurities in a non-magnetic structurally disordered host. It is shown that the critical concentration of magnetic atoms for the appearance of long-range magnetic order is not influenced by fluctuations.
TL;DR: In this article, complex dielectric constants of ice Ih along the c axis are measured in a wide range of temperature and frequency, and the reproducible temperature dependence of the static Dielectric constant and the relaxation time of the Debye component are obtained above −150°C.
Abstract: Complex dielectric constants of ice Ih along the c axis are measured in a wide range of temperature and frequency. The reproducible temperature dependence of the static dielectric constant and the relaxation time of the Debye component are obtained above –150°C. The static dielectric constant obeys a Curie-Weiss law where the extrapolated Curie-Weiss temperature is 46 K and the Curie-Weiss constant is 22520 K. Activation energies at high and low temperatures are 13.2 and 5.4 Kcal/mol respectively.