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Showing papers on "Magnetic anisotropy published in 1983"


Journal ArticleDOI
TL;DR: In this paper, the temperature dependence of the magnetic hyperfine field of microcrystalline goethite has been studied in detail and the results have been compared to the behaviour of well-crystallized Goethite.

315 citations


Journal ArticleDOI
TL;DR: In this paper, a low-temperature approximation for the reduction in the magnetic hyperfine splitting of the Mossbauer spectrum of a microcrystal was derived for arbitrary magnetic energy, and explicit expressions for particles with special types of magnetic anisotropy and for particles exposed to external magnetic fields.

296 citations


Journal ArticleDOI
TL;DR: In this article, it was calculated that spin-orbit coupling induces a predominant orbital magnetic moment antiparallel to the spin moment in the spin-polarized energy bands of UN.
Abstract: It is calculated that spin-orbit coupling induces a predominant orbital magnetic moment ($\ensuremath{-}1.5{\ensuremath{\mu}}_{\mathrm{B}}$) antiparallel to the spin moment ($1.0{\ensuremath{\mu}}_{\mathrm{B}}$) in the spin-polarized energy bands of UN. The shape of the magnetic form factor, pressure dependence of the moment, and presence of large magnetic anisotropy then become compatible with itinerant-electron theory.

150 citations


Journal ArticleDOI
TL;DR: The relationship among the anisotropy of magnetic susceptibility, the finite strain and the characteristic remanent magnetization (ChRM) have been investigated in deformed red sediments from the Alpes Maritimes in southeast France.

115 citations


Book ChapterDOI
01 Jan 1983
TL;DR: The magnetic susceptibility of diamagnetic materials has been shown to be at most 10−3 to 10−5 SI as discussed by the authors, where SI is the number of magnetic moments acquired per unit field applied.
Abstract: A magnetic field is produced by the movement of an electrical charge. So, at the lowest level, the movement of an electron results in the creation of a magnetic field. Electrons will normally spin about their axes and also orbit their nucleus and therefore have two types of motion that can produce magnetic fields. All substances can thus be regarded as being magnetic at an atomic level and can be classified into two types. In diamagnetic substances the electron shells are full and the precession of electron orbits when placed in a magnetic field results in the creation of a magnetic field in the opposite direction to the applied field. The magnetization acquired per unit field applied, the magnetic susceptibility, is small, less than 10−5 SI. In substances in which the electron shells are incomplete, paramagnetic materials, each atom has a magnetic moment due to the uncompensated electron spins. When placed in a magnetic field, the electron orbits precess but the magnetic moment is aligned in the same direction as the applied field and is generally stronger than that of diamagnetic substances, having susceptibilities of the order of 10−3 to 10−5 SI.

102 citations


Journal ArticleDOI
TL;DR: In this article, a method of separating low field susceptibility anisotropies due to ferrimagnetics and the matrix, proposed hitherto in cases where the principal axis of these two components are merged, is generalized in case where the axes are distinct.

83 citations


Journal ArticleDOI
TL;DR: The results of a detailed inelastic neutron scattering study of the spindynamics in CsNiF3 in an external magnetic field are presented in this paper, where results have been obtained for different combinations of the correlation function (α=x, y, z) in order to analyse theH, T, qc-dependence of both, the central component and the spinwave scattering.
Abstract: The results of a detailed inelastic neutron scattering study of the spindynamics in CsNiF3 in an external magnetic field are presented. Results have been obtained for different combinations of the correlation function (α=x, y, z) in order to analyse theH, T, qc-dependence of both, the central component and the spinwave scattering. These results cannot be explained by a multispin-wave theory alone, but it is necessary to introduce solitons in order to describe the experimental findings. It is found that under certain conditions the contribution from solitons and from two-spinwave processes have the same size. These results show that the spindynamics in this system in fields 2.5kOe 15K this picture breaks down probably due to the finite size of the easy plane anisotropy energy.

72 citations


Journal ArticleDOI
P.C. Scholten1
TL;DR: The maximal attainable magnetization in a magnetic fluid is limited by the magnetization of the core material, the requirements for stability towards aggregation, and the space needed for the carrier fluid as discussed by the authors.

69 citations


Journal ArticleDOI
TL;DR: Magnetization and Mossbauer studies of RFe5Al7(R = Y, Sm to Lu, ThMn12 crystal structure) in magnetic fields up to 50 kOe and temperatures 4.1 to 500 K have been performed as discussed by the authors.

65 citations


Journal ArticleDOI
TL;DR: In this paper, the magnetic flux distribution in the grain-oriented steel core transformer is investigated with the finite element method and a mathematical model (Model II) is obtained for the reluctivity tensor.
Abstract: In this work the magnetic flux distribution in the grain-oriented steel core transformer is investigated with the finite element method. A mathematical model (Model II) is obtained for the reluctivity tensor. The model, optimized by means of experimental values of the B-H curve, predicts different directions of the magnetization field, not just along the rolling and transverse directions of the material. The results are the flux maps, as well as the reactance values and the electrodynamic forces on the windings. These results, obtained by means of the isotropic model and the anisotropic first model [1], are compared with the experimental ones.

58 citations


Journal ArticleDOI
TL;DR: The magnetic susceptibilities χ of frustrated triangular lattice antiferromagnets CsVCl 3 and VX 2 (X=Cl, Br and I) have been measured by means of the conventional Faraday-type as well as the SQUID magnetometers.
Abstract: Magnetic susceptibilities χ of the frustrated triangular lattice antiferromagnets CsVCl 3 and VX 2 (X=Cl, Br and I) have been measured by means of the conventional Faraday-type as well as the SQUID magnetometers. The χ- T curve of CsVCl 3 shows a typical 1D-like character in agreement with the early work by Niel et al . At T < T N , χ c increases rapidly with decreasing T , whereas χ a stays at a constant value. The χ- T curve in VX 2 which are thought to be 2D-like systems is very flat and shows an anomaly at T N . Surprizingly, however, no anisotropy could be detected below T N . This suggests that the transition is quite different from the conventional one for the non-frustrated antiferromagnetic systems and a magnetic liquid state is formed in the ordered state.

Journal ArticleDOI
K. Okamoto1
TL;DR: In this article, a method to determine the easy axis of films with uniaxial magnetic anisotropy using spontaneous Hall effect is presented, and its validity is verified by the experiments.

Journal ArticleDOI
TL;DR: In this article, the magnetic structures of the antiferromagnetic layered compounds Co1/3NbS2 and Co 1/3TaS2 were examined using single-crystal neutron photographic and counting methods.
Abstract: The authors have examined the magnetic structures of the antiferromagnetic layered compounds Co1/3NbS2 and Co1/3TaS2 using single-crystal neutron photographic and counting methods. The magnetic structure of Co1/3NbS2 has been determined in detail, and has an orthohexagonal unit cell, containing two Co atoms, arranged on the 'hexagonal ordering of the first kind' scheme. The different symmetries of the crystallographic and magnetic unit cells leads to a complicated domain structure. A large part of the magnetisation in this material is localised on the Co atoms, although the magnetic moment of the Co2+ ion is approximately 10% lower than that of the corresponding spin-only moment. The magnetic structure of the related material, Co1/3TaS2, which has the same crystal structure as Co1/3NbS2, is very different, and is a triangular antiferromagnetic structure although for this material only the unit cell has been determined.

Journal ArticleDOI
TL;DR: In this paper, the magnetic anistropy induced by constant tensile stress and constant torsional strain annealing has been studied for liquid quenched alloys of the compositions (FexCo1−x)75Si15B10 (x = 0.1−1.0) and (Fe0.11Co0.89)72Mo3Si 15B10.

Journal ArticleDOI
TL;DR: In this paper, a model based on the idea of localized magnetic moments is presented which allows to calculate the local magnetic moment expectation values of FeNi alloys, and the model allows the iron magnetic moments to orient parallel or antiparallel to the magnetization axis, depending on the local environment.
Abstract: A model based on the idea of localized magnetic moments is presented which allows to calculate the local magnetic moment expectation values of FeNi alloys. The only parameters of the model are the exchange integralsJ FeFe,J FeNi,J NiNi. By assuming a “mixed” exchange interaction the concentration dependence of the exchange integralsJ FeFe andJ FeNi is calculated. The model allows the iron magnetic moments to orient parallel or antiparallel to the magnetization axis, depending on the local environment. It explains the magnetic abnormalies of FeNi Invar alloys as for example the concentration dependence of the mean magnetic moment and the Curie temperatures as well as the characteristic “flat” courves of the spontaneous magnetization.

Journal ArticleDOI
TL;DR: In this article, Mossbauer studies of suspensions of 60 A Fe 3 O 4 microcrystals in acetone with and without oleic acid indicate that chemisorption of OO results in an increase in the surface contribution to the magnetic anisotropy energy constant.

Journal ArticleDOI
TL;DR: In this article, the magnetic anisotropy constants for an aligned MnAlC magnet were measured from magnetization curves with the magnetic field parallel and perpendicular to the alignment axis.
Abstract: The magnetic anisotropy constants K1 and K2 have been measured for an aligned MnAlC magnet. The information is extracted from magnetization curves with the magnetic field parallel and perpendicular to the alignment axis. The anisotropy field HA =2(K1+2K2)/IS (IS is the saturation magnetization) was determined from a break point in a plot of the perpendicular magnetization against the inverse square of the field. K1 and K2 were then found from modified Sucksmith–Thomson plots. The data is used to calculate the 180° wall energies and widths and an estimate of the temperature coefficient of coercive field variation is made and compared with experiment.

Journal ArticleDOI
TL;DR: The magnetic anisotropy of several artificially constructed samples has been measured with different types of instruments in several laboratories as discussed by the authors, but the magnitude of the anisotropic determined by the Digico anisosotropy delineator is incorrect.

Journal ArticleDOI
TL;DR: Magnetic measurements on hexagonal single crystals of M 2 Mo 3 O 8 (M = Mn, Fe, Co and Ni) are reported in this article, which indicates that the magnetic spins' preferred orientation is along the hexagonal axis.

Journal ArticleDOI
TL;DR: The magnetic properties of amorphous Fe92Zr8 and Fe90Zr10 alloys have been studied by 57Fe Mossbauer and magnetization measurements as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, a two-dimensional Heisenberg spin system with ferromagnetic exchange, local random anisotropy, and coherent anisotropic anisophotonicity was studied in two dimensions.


Journal ArticleDOI
TL;DR: In this article, the magnetic phase transitions in a second-stage CoCl 2 -graphite intercalation compound based on a single crystal of Kish graphite have been investigated by elastic neutron scattering, magnetization, magnetic susceptibility, and specific heat measurements.

Patent
20 Dec 1983
TL;DR: A thermomagnetic recording and reproducing system for use in optical magnetic disc apparatus was proposed in this article, where at least a first layer (1) of soft magnetic material having an easy axis of magnetization normal to the layer surface, a transparent non-magnetic intermediate layer (2), a second layer (3), a metal film or semi-metal film adjacent to the second magnetized layer are superposed on one another to form a recording medium.
Abstract: A thermomagnetic recording and reproducing system for use in optical magnetic disc apparatus wherein at least a first layer (1) of soft magnetic material having an easy axis of magnetization normal to the layer surface, a transparent non-magnetic intermediate layer (2), a second layer (3) of soft magnetic material having an easy axis of magnetization normal to the layer surface and a metal film or semi-metal film (4) adjacent to the second magnetized layer are superposed on one another to form a recording medium (5) In recording, a bias magnetic field is applied to the first and second magnetized layers (1) and (3) so that the magnetized layers are magnetized to have a single magnetic domain over their whole surfaces and a magnetization directed perpendicular to the layer surface Then, a light pulse having a first wavelength of, for example, a relatively short wavelength and of which optical absorptance in the magnetized layer is relatively high is made incident on the single magnetic domain of the first magnetized film (1) to form a cylindrical magnetic domain magnetized in the direction opposite to the magnetization direction by the applied bias magnetic field, thereby recording information bits on the first magnetized layer (1) A light pulse having a second wavelength of, for example, a relatively long wavelength which passes through the first and second magnetized layers (1) and (3) is made incident on the single magnetic domain of the second magnetized layer (3) to form a cylindrical magnetic domain magnetized in the direction opposite to the magnetization direction by the applied bias magnetic field The information is read out from the medium (5) on which the recording was made as above by utilizing the magneto optic effect

Journal ArticleDOI
TL;DR: In this paper, the magnetostrictions and magnetization curves of rare earth-Fe 1.95 alloys have been measured under compressive stress up to 48 MPa.
Abstract: The magnetostrictions and magnetizations of highly magnetostrictive rare earth-Fe 1.95 alloys have been measured under compressive stress up to 48 MPa. The shape of the magnetostriction and magnetization curves depend upon the relative concentrations of Tb, Dy, and Ho and the degree of crystallite orientation.

Journal ArticleDOI
TL;DR: Magnetostriction and magnetic core loss at high frequency up to 100 kHz were investigated together with crystallization temperature, saturation magnetization, and magnetic permeability for amorphous (Fe1−xNbx)zSi88−zB12 alloys in this paper.
Abstract: Magnetostriction and magnetic core loss at high frequency up to 100 kHz were investigated together with crystallization temperature, saturation magnetization, and magnetic permeability for amorphous (Fe1−xNbx)zSi88−zB12 alloys. Crystallization temperature significantly rises with Nb addition, particularly in the high z region. Magnetostriction decreases with increasing Nb content and z value. Magnetic core loss decreases and magnetic permeability increases with decreasing magnetostriction. Magnetic core loss reduction due to Nb addition were analyzed to be mainly attributed to domain width reduction through the decrease of magnetostriction.

Journal ArticleDOI
TL;DR: In this paper, the magnetic phase is Fe21Pr3B with a primitive tetragonal lattice and exhibits high magnetocrystalline anisotropy with a single easy axis along.

Journal ArticleDOI
TL;DR: In this article, temperature and field dependences of magnetization, paramagnetic susceptibility, magnetic anisotropy and neutron diffraction for CuxZn1-xCr2Se4 spinels are investigated.
Abstract: We present detailed results concerning temperature and field dependences of magnetization, paramagnetic susceptibility, magnetic anisotropy and neutron diffraction for CuxZn1-xCr2Se4 spinels. Particular emphasis is put on the gradual transition from helimagnetism to ferromagnetism as a function of concentration x. The transition takes place through an intermediate structure for 0.05 ≤ x ≤ 0.8 with the ferromagnetic component growing with concentration. It is suggested that a double exchange mechanism predominates as x increases and this can be regarded as the origin of the transition.

Book ChapterDOI
H. Fujimori1
01 Jan 1983

Journal ArticleDOI
TL;DR: In this article, accurate and detailed measurements of average magnetic susceptibility (4-100 K) and magnetization (2-20 K and 10-50 kOe) are reported on a number of high spin iron prophyrins, namely protoporphyrin, octaethylporphyrin and deuteroporphrin iron(III) chlorides.
Abstract: Accurate and detailed measurements of average magnetic susceptibility (4–100 K) and magnetization (2–20 K and 10–50 kOe) are reported on a number of high spin iron (III) prophyrins, namely protoporphyrin‐, octaethylporphyrin‐, and deuteroporphyrin iron (III) chlorides. Adequate precautions were taken to ensure that the crystallites did not orient during the magnetization measurements, in high magnetic fields at low temperatures. The experimental magnetization data show complete saturation below 4 K at magnetic fields above 40 kOe and the saturation moment 〈μ〉 lies between 3.0–3.4 in these compounds, indicating large deviation from the expected value of 5.0, due to sizeable zero‐field splitting. The magnetization results at low temperatures show varying degrees of exchange interaction, which was considered within molecular field framework to quantitatively account for the data. A fit to the data gave reasonable values for the zero‐field splitting and exchange‐interaction parameters.