Showing papers on "Curie–Weiss law published in 1989"
18 citations
TL;DR: In this article, the magnetic fluctuations in a sample of Fe 2 P at a range of temperatures above its Curie point have been investigated by polarised neutron scattering, and spin correlations up to a distance of 12 A are found to persist up to at least 780 K (3.7 T C ).
17 citations
14 citations
TL;DR: The dielectric constant of undoped, polycrystalline barium titanate in the paraelectric phase was obtained from the complex impedance plane representation in the 180-400°C temperature range, between 5 Hz and 13 MHz.
Abstract: The dielectric constant of undoped, polycrystalline barium titanate in the paraelectric phase was obtained from the complex impedance plane representation in the 180–400°C temperature range, between 5 Hz and 13 MHz. A Curie-Weiss behavior is observed, with a Curie constant C o = 10.48 × 104 (K). These results are discussed and compared with results obtained with fixed frequency measurements.
10 citations
TL;DR: In this article, a tilting three-angle Mossbauer method was applied to see the changes of the 57Fe hyperfine field directions and intensities due to stress-annealing above the Curie temperature.
Abstract: To produce magnetic anisotropy in amorphous alloys, stress-annealing above the Curie temperature was substituted for the common thermomagnetic treatment. A tilting three-angle Mossbauer method was applied to see the changes of the57Fe hyperfine field directions and intensities due to this procedure. The resulting pictures of the domain orientations distribution in the Fe80Cr2B14Si4 and Fe40Ni40B20 amorphous alloys are compared with the measured magnetic anisotropies and domain structures.
9 citations
TL;DR: In this paper, three magnetic field ranges corresponding to different critical current density j c behavior have been found out and they correlate with grain magnetization changes, and they are shown to depend linearly on the sample cross-section due to the "own" magnetic field induced by the flowing current.
Abstract: Three magnetic field ranges corresponding to different critical current density j c behavior have been found out. They correlate with grain magnetization changes. The inverse critical current density is shown to depend linearly on the sample cross-section due to the “own” magnetic field induced by the flowing current.
9 citations
TL;DR: In this paper, an electron-doped superconductor Nd2-xCexCuO4 (with nominal composition x=0.15) was investigated and the normal state susceptibility obeys the Curie-Weiss law in a low external field (5 G) but in higher fields a deviation from this behaviour is observed at T approximately = 40 K.
Abstract: Magnetic investigations of the electron-doped superconductor Nd2-xCexCuO4 (with nominal composition x=0.15) are reported. In a low external field (5 G) the normal state susceptibility obeys the Curie-Weiss law but in higher fields a deviation from this behaviour is observed at T approximately=40 K. From the high-temperature data the value of the Curie temperature theta =-70 K is obtained, indicating antiferromagnetic interactions. Hysteresis measurements give the critical current density of jc=2.3*102 A cm-2 in a field of 30 G. From the logarithmic time dependence of the thermoremanent magnetisation we estimate an activation energy of Uo=0.05 eV for thermally induced flux creep.
5 citations
TL;DR: In this paper, a graphical treatment for the relationship between M, T, and the applied magnetic field, B 0, was presented. And exact expressions for T(M,B 0) were obtained for spin 1/2 and spin 1, respectively.
Abstract: The conventional analysis of the Weiss mean field theory of a ferromagnet uses a graphical treatment for the relationship between M, T, and the applied magnetic field, B0. It is shown that, for spin 1/2 and spin 1, exact expressions may be obtained for T(M,B0), and the behavior of the function is analyzed.
5 citations
5 citations
TL;DR: In this article, the results of magnetic measurements performed on U(NixAl1−x)2 alloys in the temperature range 4.2 and 800 K are reported, which suggest a gradual suppression of spin fluctuations.
4 citations
TL;DR: In this paper, the authors investigated the pressure effect on the Curie temperature of Fe80 - xMnxB20 (x = 6, 10 and 20) amorphous alloys.
TL;DR: In this article, a diamagnetic "Curie-Weiss law" was found in various organic liquids and their mixtures by using the magnetic birefringence effect in pulsed magnetic fields up to 40 T.
Abstract: A diamagnetic “Curie-Weiss law” is found in various organic liquids and their mixtures by using the magnetic birefringence effect in pulsed magnetic fields up to 40 T. An extended Langevin theory of diamagnetism is applied and the Curie-Weiss constant, which reflects the intermolecular interaction, is determined for many liquids and mixtures.
TL;DR: In this paper, the pressure effect on the Curie temperature indicates a linear relationship between (l/Tc)dTc/dP and Tc, implying that the magnetic state is heterogeneous and it is not changed by addition of B.
Abstract: Fe-Nd and Fe-Nd-B amorphous alloys were prepared by dc sputtering in order to investigate the magnetic state and the thermal expansion anomaly. The pressure effect on the Curie temperature indicates a linear relationship between (l/Tc)dTc/dP and Tc, implying that the magnetic state is heterogeneous and it is not changed by addition of B. The pressure effect on the Curie temperature of Fe-Nd amorphous alloys decreases with increasing Nd content and the magnitude is comparable with that of Fe-Ni crystalline Invar alloys. The thermal expansion anomaly is remarkably large, accompanying a shrinkage in a wide range of temperature. It should be noted that a distinct anomaly is observed even well above the Curie temperature. This peculiar behavior is closely related to the magnetic clusters existing above the Curie temperature.
TL;DR: In this paper, the initial susceptibility chi of a textured frozen dilute magnetite (Fe/sub 3/O/sub 4/) was measured in the temperature range 80-180 K for different freezing magnetic fields H/sub f/.
Abstract: The initial susceptibility chi of a textured frozen dilute magnetite (Fe/sub 3/O/sub 4/) ferrofluid has been measured in the temperature range 80-180 K for different freezing magnetic fields H/sub f/. The texture is induced by cooling the ferrofluid to the solid state in the presence of an H/sub f/ of less than 220 Oe. The frozen ferrofluid exhibits Curie-Weiss behaviour. Using these results it is found that chi varies linearly with the square of H/sub f/, which agrees with a theoretical model for a noninteracting textured fine particle system in a solid matrix. It is suggested that the presence of particle aggregates in the ferrofluid can be detected through the study of the ordering temperature. >
TL;DR: In this article, low temperature in situ119Sn Mossbauer effect (ME) studies in vapor quenched amorphous MnxSn1−x (0.09
Abstract: We present systematic low temperature in situ119Sn Mossbauer effect (ME) studies in vapor quenched amorphous MnxSn1−x (0.09
TL;DR: In this article, the field dependence of the critical current density in the systems REBa2Cu3O7−δ and YBa2(Cu1-xFex)3O 7 −δ was studied b y magnetization measurements at 4.2 K in a pulsed magnetic field up to 50 T.
Abstract: Field dependence of the critical current density in the systems REBa2Cu3O7−δ and YBa2(Cu1-xFex)3O7−δ was studied b y magnetization measurements at 4.2 K in a pulsed magnetic field up to 50 T. In the system REBa2Cu3O7−δ, Jc is found to be correlated to the saturation moment of the rate earth ion.
TL;DR: In this article, the effect of magnetic field applied during casting was investigated by comparing several parameters such as magnetization, coercive force, magnetic anisotropy, Curie and crystallization temperature, and the domain structure of the ribbons.
Abstract: Fe-B metallic glass ribbons were prepared by melt-spinning in longitudinal and transversal magnetic field, and without an applied magnetic field. The effect of the magnetic field applied during casting was investigated by comparing several parameters such as magnetization, coercive force, magnetic anisotropy, Curie and crystallization temperature, and the domain structure of the ribbons.
TL;DR: In this article, the magnetic behavior of a system consisting of localized electrons coupled to conduction electrons and submitted to an axial crystal field at T = 0 K was investigated within the framework of the molecular field approximation.
TL;DR: The self-consistent local moment in nickel above the Curie temperature has been calculated for various amounts of short-range magnetic order as discussed by the authors, indicating that a moderate degree of short range magnetic order is required for a self consistent local moment to be sustained.
TL;DR: In this paper, the anisotropy of both critical current density and paramagnetic rare-eart was deduced from isothermal hysteresis cycles from single crystals of ErBa 2 Cu 3 O 7 and HoBa 2 Co 7 in magnetic fields up to 180 kOe applied parallel to the c -axis or in the ( ab ) plane in the 4.2-200 K temperature range.
Abstract: Magnetization measurements were performed on single crystals fo ErBa 2 Cu 3 O 7 and HoBa 2 Cu 3 O 7 in magnetic fields up to 180 kOe applied parallel to the c -axis or in the ( ab ) plane in the 4.2–200 K temperature range. From isothermal hysteresis cycles the anisotropy of both critical current density and paramagnetic rare-eart were deduced.
TL;DR: The magnetic properties of the monophasic superconductor Tl 0.5Pb0.5Ca 0.8Er0.2Sr2Cu2Oy with a TlCaBa2Cu 2O7-type (1122) structure have been studied using a combination of magnetisation and ESR (Electron Spin Resonance) measurements as discussed by the authors.
Abstract: The magnetic properties of the monophasic superconductor Tl0.5Pb0.5Ca0.8Er0.2Sr2Cu2Oy with a TlCaBa2Cu2O7-type (1122) structure have been studied using a combination of magnetisation and ESR (Electron Spin Resonance) measurements. This new material exhibits a superconductive transition (Tc) around 110 K, above which the temperature dependence of the magnetic susceptibility can be described by a Curie-Weiss law. Below Tc the co-existence of superconductivity and paramagnetism was observed.
TL;DR: In this article, the electric and magnetic measurements have been carried out on a polycrystalline single phase SmBa2Cu3O7 sample and the normal state susceptibility of it consists of a temperature-dependent Curie-Weiss paramagnetic term with an effective Bohr magneton number peff=1.1 and the temperature θ=38 K and temperature independent terms: the Van Vleck and Pauli paramagnetism and the ionic core and Landau diagmagnetism.
Abstract: The electric and magnetic measurements have been carried out on a polycrystalline single phase SmBa2Cu3O7 sample. The normal state susceptibility of it consists of a temperature-dependent Curie-Weiss paramagnetic term with an effective Bohr magneton number peff=1.1 and the Curie-Weiss temperature θ=38 K and temperature-independent terms: the Van Vleck and Pauli paramagnetism and the ionic core and Landau diagmagnetism. The Pauli susceptibility derived from the temperature-independent normal-state susceptibility of YBa2Cu3O7 is so large that it is due to the strong electron-electron interactions among conduction electrons. We deduce the low critical field Hc1(1.5 K), which is 580 Oe and the critical magnetization current density which is of the order of 104 A/cm2 at 5 kOe and decreases with increasing applied field from the magnetization hysteresis loop of SmBa2Cu3O7 for fields up to 60 kOe and temperature at 1.5 K. Some magnetic and superconductive parameters such as Hc(0), kGL, χ, λ, etc. are also given by using the values of the low and upper critical fields and the energy gap within the Ginzburg-Landau theory.
TL;DR: In this paper, the changes of some magnetic parameters of Fe85−xCrxB15 glassy metals due to n-irradiation are investigated, and it is found that the spin-wave stiffness constant D, the exchange constant Aex, and the Curie temperature Tc gradually increase with n-IRradiation.
Abstract: The changes of some magnetic parameters of Fe85−xCrxB15 glassy metals due to n-irradiation are investigated. The mean magnetic moment per transition metal atom exp remains almost constant after n-irradiation. It is found that the spin-wave stiffness constant D, the exchange constant Aex, and the Curie temperature Tc gradually increase with n-irradiation. However, the coercivity shows the opposite behaviour.
TL;DR: Ferrimagnetic compounds of the series Er(FexCu1−x)2 (x 1.0, 0.95 and 0.8) are investigated by magnetization, a. c. magnetic susceptibility, Mossbauer effect, and magnetostriction measurements as discussed by the authors.
Abstract: Ferrimagnetic compounds of the series Er(FexCu1−x)2 (x 1.0, 0.95, 0.9, 0.85, and 0.8) are investigated by magnetization, a. c. magnetic susceptibility, Mossbauer effect, and magnetostriction measurements. With decreasing x-value, the Curie temperature, the effective iron moments as well as the average magnetic moment of the iron sublattice decreases monotonously.
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TL;DR: The analysis of the magnetization data and of the distribution of Co−Ti among the iron sublattices suggest that the Gorter spin arrangement is no longer valid.
Abstract: Fine powder samples of substituted Barium M-type haxaferrites with composition BaFe12−2xCoxTixO19 (0.72
TL;DR: In this article, the magnetic properties of a d-dimensional uncharged ideal paragas in a uniform magnetic field were examined and the crossover between these limits was evaluated numerically, observing that the parafermions can be characterized by Fermi-Dirac behavior.
Abstract: The magnetic properties of a d-dimensional uncharged ideal paragas in a uniform magnetic field are examined. For parastatistics parameter p = ∞ (bosons) there is Bose-Einstein condensation for d α > 1 with spontaneous magnetization, and for 1 d α ≦2 there is a divergent magnetic susceptibility at zero magnetic field. For finite p (parafermions) we obtained the asymptotic limit behavior of low and high temperature of the magnetic susceptibility. The crossover between these limits is evaluated numerically, observing that the parafermions can be characterized by Fermi-Dirac behavior.