Showing papers on "Magnetization published in 1984"
TL;DR: In this paper, a new compound composed of Nd, Fe, and a small quantity of B (about 1 wt. %) has been found, which has a tetragonal structure with lattice constants a=0.880 nm and c=1.221 nm.
Abstract: A new compound composed of Nd, Fe, and a small quantity of B (about 1 wt. %) has been found, which has a tetragonal structure with lattice constants a=0.880 nm and c=1.221 nm. This phase, which has the approximate composition, 12 at. % Nd, 6 at. % B and balance Fe, possesses remarkable magnetic properties. From the approach to saturation an anisotroy constant of about 3.5 MJ/m3 can be calculated, while saturation magnetization amounts to 1.35 T. The magnetization versus temperature curve shows a Curie temperature of 585 K, which is much higher than those of the Fe and light rare earth binary compounds. Based on the new compound, sintered permanent magnets have been developed which have a record high energy product. Permanent magnet properties and physical properties of a typical specimen which has the composition Nd15B8Fe77 are as follows: Br =1.23 T, HcB =880 kA/m, HcI =960 kA/m, (BH)max =290 kJ/m3, temperature coefficient of Br =−1260 ppm/K, density=7.4 Mg/m3, specific resistivity=1.4 μΩm, Vickers hardn...
2,525 citations
TL;DR: In this article, a martensitic phase transition to a complex tetragonal structure occurs on cooling below 202 K. Reasons for the structural transformation are discussed, and details of the low temperature crystallographic superlattice and magnetic structure are determined.
Abstract: Magnetization, magnetic susceptibility, optical microscopy, X-ray diffraction and neutron diffraction measurements have been made on a quenched sample of Ni2MnGa. Room-temperature neutron diffraction patterns indicate a highly ordered Heusler alloy, L21 type, structure. The alloy is ferromagnetic with a Curie temperature of 376 K, and a magnetic moment of 4·17μB largely confined to the Mn sites, but probably with a small moment <07·3μB associated with the Ni sites. A martensitic phase transition to a complex tetragonal structure occurs on cooling below 202 K. Neutron diffraction oscillation photographs taken using the D12 facility at Institut Laue Langevin, Grenoble, and low-temperature powder neutron diffraction data enabled details of the low temperature crystallographic superlattice and magnetic structure to be determined. Reasons for the structural transformation are discussed.
1,048 citations
TL;DR: In this article, a mathematical theory of hysteresis in ferromagnetic materials is presented based on existing ideas of domain wall motion and domain rotation, which is shown to occur as a result of impedances to changes of magnetization such as when domain walls are pinned.
Abstract: A mathematical theory of hysteresis in ferromagnetic materials is presented based on existing ideas of domain wall motion and domain rotation. Hysteresis is shown to occur as a result of impedances to changes of magnetization such as when domain walls are pinned, while the mutual interactions of the magnetic moments are shown to be of secondary importance in this respect. An equation for the anhysteretic or ideal magnetization curve is derived based on a mean field approximation and this is shown to be dependent on the mutual interactions of the moments but independent of impedances such as pinning. The introduction of a term which measures the impedance to changes in magnetization leads to a simple differential equation of state for a ferromagnet which exhibits all the features of hysteresis. Some modifications of the simple model are necessary in order to bring the solution closer to the real situation. Results are presented which show all the features of hysteresis such as initial magnetization curve, major hysteresis loops, and minor hysteresis loops in excellent agreement with experimental results.
480 citations
Book•
01 Jan 1984
TL;DR: In this article, the magnetization process in titanomagnetites was studied and the magnetic mineralogy of extra-terrestrial materials was discussed. But the results were limited to the case of a single ion anisotropy.
Abstract: 1 Introduction to the magnetism of rocks.- 1.1 Rocks as magnetic information stores.- 1.2 The recorded information.- 1.3 Rock and mineral magnetism.- 1.4 Magnetism-some preliminaries.- 2 Magnetic minerals in rocks.- 2.1 The magnetic mineral systems.- 2.1.1 The titanomagnetites.- 2.1.2 The titanomaghemites.- 2.1.3 Haematite and the haematite-ilmenite solid solution.- 2.1.4 The pyrrhotites.- 2.1.5 Other iron-bearing minerals.- 2.2 The magnetic mineralogy of igneous rocks.- 2.3 The magnetic mineralogy of sediments.- 2.4 The magnetic mineralogy of extra-terrestrial materials.- 2.5 Summary.- Selected bibliography.- 3 The atomic basis of magnetism.- 3.1 The electron spin the transition elements.- 3.2 Exchange.- 3.3 Curie temperatures of spinel oxides.- 3.4 Magnetocrystalline anisotropy.- 3.4.1 Dipolar anisotropy.- 3.4.2 Single ion anisotropy.- 3.4.3 Anisotropic exchange.- 3.4.4 Magnetocrystalline anisotropy constants.- 3.5 Induced anisotropy.- 3.6 Categories of magnetic behaviour.- 3.6.1 Diamagnetism and paramagnetism.- 3.6.2 Antiferromagnetism.- 3.6.3 Ferrimagnetism and ferromagnetism.- 3.7 Summary.- Selected bibliography.- 4 The magnetization process.- 4.1 The demagnetizing field-shape anisotropy.- 4.2 Domains and domain walls.- 4.3 The magnetization process.- 4.3.1 The monodomain case.- 4.3.2 The multidomain case.- 4.3.3 The magnetization process near the monodomain/multidomain boundary.- 4.3.4 Alternating field demagnetization ('fixed switching field' model).- 4.3.5 Rotational hysteresis.- 4.3.6 Particle-particle interactions.- 4.4 The time-dependence of magnetization-equilibrium and thermal agitation.- 4.4.1 Equilibrium and disequilibrium.- 4.4.2 Approach to equilibrium.- 4.4.3 The time scale.- 4.4.4 Magnetic properties.- 4.4.5 Viscous magnetization.- 4.5 Summary.- Selected bibliography.- 5 Thermoremanent magnetization.- 5.1 The mechanism-definitions of blocking temperature.- 5.2 TRM models.- 5.2.1 Aligned monodomain grains.- 5.2.2 A random array of monodomain grains.- 5.2.3 Multidomain grains.- 5.2.4 TRM near the monodomain/multidomain boundary.- 5.3 Thermal demagnetization-partial TRM.- 5.4 Self-reversed TRM.- 5.5 Summary.- Selected bibliography.- 6 Other remanence-inducing mechanisms.- 6.1 Mechanisms in nature.- 6.1.1 Chemical remanent magnetization.- 6.1.2 Depositional remanent magnetization.- 6.1.3 Viscous remanent magnetization.- 6.1.4 Piezoremanent magnetization.- 6.2 Mechanisms in the laboratory.- 6.2.1 Anhysteretic remanent magnetization.- 6.2.2 Gyroremanent magnetization and rotational remanent magnetization.- 6.3 Summary.- Selected bibliography.- 7 Magnetic properties of titanomagnetites and titanomaghemites.- 7.1 The titanomagnetites.- 7.1.1 Intrinsic properties.- 7.1.2 The magnetization process in titanomagnetites.- 7.1.3 Weak field remanences in titanomagnetites.- 7.2 The titanomaghemites.- 7.2.1 Intrinsic properties.- 7.2.2 The magnetization process.- 7.2.3 The inversion of titanomaghemites.- 7.2.4 Weak field remanences.- 7.3 Multiphase products of the oxidation of titanomagnetite.- 7.3.1 Intrinsic properties.- 7.3.2 The magnetization process.- 7.3.3 Weak field remanence.- 7.4 Summary.- 8 Magnetic properties of other mineral systems.- 8.1 Haematite.- 8.1.1 Intrinsic properties.- 8.1.2 The magnetization process.- 8.1.3 Weak field remanence.- 8.2 The haematite-ilmenite solid solution.- 8.2.1 Intrinsic properties.- 8.2.2 The magnetization process.- 8.2.3 Weak field remanence.- 8.3 The pyrrhotites.- 8.3.1 Intrinsic properties.- 8.3.2 The magnetization process.- 8.3.3 Weak field remanence.- 8.4 Goethite.- 8.5 Iron.- 8.6 Alteration products of non-magnetic minerals.- 8.7 Summary.- 9 Applications of rock and mineral magnetism.- 9.1 Introduction.- 9.2 Physical models-the acquisition and removal of weak field remanences.- 9.2.1 Palaeomagnetism.- 9.2.2 Palaeointensity determinations.- 9.2.3 Geological applications-thermal histories.- 9.2.4 Magnetic granulometry.- 9.3 Determination of the composition, concentration and microstructure of the magnetic mineral fraction in a rock (or other material).- 9.3.1 Composition.- 9.3.2 Concentration.- 9.3.3 Microstructure.- 9.4 Connections in planetary physics-the magnetization of planetary crusts.- 9.5 Summary.
457 citations
TL;DR: In this article, the lattice constants and the X-ray density of ternary tetragonal compounds of the composition R 2 Fe 14 B were determined for R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu.
249 citations
TL;DR: In this article, a fixed spin-moment (FSM) method, which allows one to calculate the total energy as an explicit function of the magnetisation, is introduced.
Abstract: The cubic Laves phase of YCo2 is near a transition from a paramagnetic to a magnetically ordered state. Self-consistent energy-band calculations yield the total energy and the magnetic moment as functions of volume. The new fixed spin-moment (FSM) method, which allows one to calculate the total energy as an explicit function of the magnetisation, is introduced. At the theoretical equilibrium volume YCo2 is found to be a strongly enhanced Pauli paramagnet, but at a slightly larger lattice constant a metamagnetic transition seems possible. Its occurrence can be understood on the basis of a double minimum in the total energy obtained from the present FSM calculations, which lead to an estimated critical field of about 350 T. In the magnetic state the Y moment is coupled antiferromagnetically to the Co moment.
244 citations
TL;DR: In this article, the authors describe low-frequency electric and magnetic noise observed at low altitudes over the auroral zone, and two general models are discussed to interpret these observations, one based on static electric and magnetar fields imbedded in the ionosphere and the other based on Alfven waves propagating along the magnetic field lines.
Abstract: Dynamics Explorer 1 measurements of intense low-frequency electric and magnetic noise observed at low altitudes over the auroral zone are described. The intensity of both the electric and magnetic fields decreases rapidly with increasing frequency. Most of the energy is at frequencies below the O(+) cyclotron frequency, and some evidence is found for a cutoff or change in spectral slope near that frequency. The magnetic to electric field ratio decreases rapidly with increasing radial distance and also decreases with increasing frequency. The polarization of the electric field in a plane perpendicular to the earth's magnetic field is essentially random. The transverse electric and magnetic fields are closely correlated, with the average Poynting flux directed toward the earth. The total electromagnetic power flow associated with the noise is substantial. Two general models are discussed to interpret these observations, one based on static electric and magnetic fields imbedded in the ionosphere and the other based on Alfven waves propagating along the auroral field lines.
238 citations
Journal Article•
TL;DR: In this article, a systematic study of the crystal structure of titanomagnetites was undertaken to characterize the effects of composition and quenching temperature on the cation distribution.
Abstract: A systematic study of the crystal structure of titanomagnetites was undertaken to characterize the effects of composition and quenching temperature on the cation distribution. Powder specimens ranging in composition from pure magnetite to a slightly nonstoichiometric ulvrispinel were synthesized at temperatures between 930 and 1350'C. Several specimens quenched from 1350'C were later annealed at 800"C for up to 95 days. Unit-cell parameters were determined by X-ray diffraction, and saturation magnetization values were measured at room temperature on a vibrating sample magnetometer. The oxygen coordinate, thermal parameters, and sublattice magnetizations were determined from neutron difraction data using profile refinement techniques. No significant diferences were found in the unit-cell parameters or magnetization resulting from different synthesis temperatures or annealing, and no change was observed in the oxygen positional parameters following annealing. Ti occupies only octahedral sites in all specimens. Temperature factors increase markedly with Ti content, indicating static positional disorder due to mixing of Fe and Ti on octahedral sites. Values of the saturation magnetization and individual sublattice magnetic moments are consistent with the cation distribution model of Akimoto and do not support models that propose a quenchable, temperature-dependent Fe2*-Fe3* distribution. Diffuse scattering in the neutron diffraction patterns suggests the presence of short-range order, possibly involving octahedral cations, but no long-range order inconsistent with space group Fd3m was found. Systematic trends in the oxygen position and unit-cell parameter as a function of composition may be influenced bv octahedral cation interactions.
212 citations
TL;DR: It appears that tissue water probes the macromolecular composition and structure in a tissue-specific fashion, and its magnitude at low fields varies by more than a factor of three, far more than does the water content of the tissues.
Abstract: It is well established that the spin-lattice magnetic relaxation rate 1/T1 of solvent protons in homogeneous protein solutions increases dramatically as the magnetic field is reduced well below the traditional NMR range. For a 5% solution of protein of 10(5) Daltons, for example, 1/T1 increases from about 50% above the pure solvent rate at 20 MHz to five times the solvent rate at 0.01 MHz. At higher fields, the effect of protein on the relaxation rate decreases progressively toward zero. 1/T1 of solvent in erythrocyte suspension behaves similarly, indicating that extracellular water has ready access to intracellular protein. We now report analogous data for samples of various mammalian tissues: we find that the data can be accommodated within the conceptual framework developed earlier for analyzing homogeneous protein solutions. It appears that tissue water probes the macromolecular composition and structure in a tissue-specific fashion. The variation of 1/T1 with field differs for each tissue, and its magnitude at low fields varies by more than a factor of three, far more than does the water content of the tissues. The relevance to contrast in NMR imaging is discussed.
162 citations
TL;DR: In this paper, the role of valence fluctuations and 4f hybridization in the magnetic ordering of cerium compounds has been explored in terms of the effects that 4f-4f interactions mediated through hybridization with conduction electrons.
Abstract: We report the results of neutron-diffraction experiments on CeM/sub 2/Si/sub 2/ (M = Ag,Au,Pd,Rh) which were performed to explore the role of valence fluctuations and 4f hybridization in the magnetic ordering of cerium compounds. All four order antiferromagnetically, the first three exhibiting structures consisting of ferromagnetic layers with moments perpendicular to the layers, which are believed to be characteristic of 4f-4f interactions mediated through hybridization with conduction electrons. CePd/sub 2/Si/sub 2/ has an anomalously small moment (0.62..mu../sub B/) in the ordered state. CeAg/sub 2/Si/sub 2/ exhibits an incommensurate longitudinal, static magnetization wave with moment and propagation direction along the a axis. The fourth compound, CeRh/sub 2/Si/sub 2/, has the highest known transition temperature (39 K) reported for cerium ordering; it exhibits another second-order transition at 27 K to a complex commensurate structure with modulated moments. The results are discussed in terms of the effects that 4f hybridization can have on ordering.
159 citations
TL;DR: The magnetic properties of rapidly quenched FeRM alloys where R=La,Y,Pr,Nd,Gd and M=B,Si,Al,Ga,Ge have been investigated over a wide range of chemical compositions as discussed by the authors.
Abstract: The magnetic properties of rapidly quenched FeRM alloys where R=La,Y,Pr,Nd,Gd and M=B,Si,Al,Ga,Ge have been investigated over a wide range of chemical compositions. The samples are generally magnetically soft in the as‐quenched state. Magnetic hardening is produced by annealing the samples around 700 °C. The best properties have been obtained in samples containing Pr and Nd together with B and Si. An energy product of 13 MGOe and a coercive field of 15 kOe have been obtained in a Fe76Pr16B5Si3 sample. The higher Fe content samples appear to be more promising with a potential energy product of 49 MGOe. Thermomagnetic data show that a structural transformation takes place upon heating the samples to 700 °C. The Curie temperature of the as‐quenched phase is around 160 °C while that of the new phase is around 320 °C. Transmission electron microscope studies show fine precipitates (∼100 A) dispersed in a matrix of different chemical composition. X‐ray and electron diffraction data indicate that the precipitates have the Fe21R3B tetragonal structure. The high anisotropy of this phase together with its fine size and distribution give rise to the observed high coercive fields.
TL;DR: In this paper, self-consistent spin-polarized energy-band calculations are used to explain the trends in the ferromagnetic moments of transition-metal alloys.
Abstract: Self-consistent spin-polarized energy-band calculations are used to explain the trends in the ferromagnetic moments oftransition-metal alloys. It is demonstrated that a large amount of magnetization data become interpretable by using the generalized Slater-Pauling curve recently introduced by Williams et al. The discussion includes Heusler alloys of both L21 and Clb structure for which exchange constants and hence the Curie temperatures can be estimated theoretically. CoMnSb is treated in detail and is shown to belong to the class of half-metallic ferromagnets first discovered by de Groot et al. Also included will be Fe3Cr and Au4V which represent interesting examples of itinerant ferromagnetism.
TL;DR: In this article, the magnetic phase diagram is constructed above 0.6 K for single crystalline Ce x La 1-x B 6 (0.03 ≦ x ≦ 1.0).
Abstract: Measurements of the magnetization process at 4.2 K and 1.3 K for magnetic field up to about 150 kOe and of the temperature dependence of the susceptibility between 4.2 K and room temperature have been done in order to investigate Kondo states of dilute and dense Kondo system in single crystalline Ce x La 1- x B 6 (0.03 ≦ x ≦1.0). The magnetic phase diagram is constructed above 0.6 K for Ce 0.5 La 0.5 B 6 , Ce 0.75 La 0.25 B 6 and CeB 6 . A largely anisotropic magnetization and the temperature dependence of susceptibility in dilute alloys indicate the \(\varGamma _{8}\) quartet Kondo state contrary to the previous report. Dependence of Kondo temperature on the Ce concentration is very weak.
TL;DR: The first crystallized melt quenched alloys to exhibit interesting hard magnetic properties were (Fe0.82B0.18)0.9Tb0.05La0.067.
Abstract: Among the first crystallized melt quenched alloys to exhibit interesting hard magnetic properties was (Fe0.82B0.18)0.9Tb0.05La0.05. The high coercive force of this alloy results from a mixture of R6Fe23 and Fe3B phases with a very fine grained microstructure (∼300 A). The hard magnetic state only exists over a narrow range of annealing temperatures due to phase decomposition and grain growth at higher temperatures. Recent results on alloys with compositions corresponding to varying ratios of R6Fe23 and Fe3B have suggested a new magnetically hard ternary phase near the composition R0.15Fe0.783B0.067. In contrast to earlier alloys, the hard magnetic state of this material remains essentially unchanged over a rather wide range of annealing temperatures up to at least 800 °C. When R is mostly Nd or Pr, isotropic magnets with energy products as high as 13 MGOe can be produced.
TL;DR: In this article, the saturation magnetization Js(T, D) of the Ni(111) films was analyzed using a high sensitivity torsion oscillation magnetometer working in UHV.
TL;DR: In this article, the effect of an ordered overlayer of Ag on the magnetism of an Fe(001) surface was studied and the role of the Ag overlayer in delocalizing the Fe surface states responsible for the increased surface magnetization and the effect on the single-particle spectra was described.
Abstract: A study of the effect of an ordered overlayer of Ag on the magnetism of an Fe(001) surface is presented. In order to understand the changes induced at the Ag/Fe interface, a series of self-consistent spin-polarized local-spin-density calculations were carried out with the use of our allelectron, full-potential, linearized augmented-plane-wave method. While the charge density is found to approach the bulk value within approximately one layer of the interface, the spin density at the interface is found to be strongly perturbed. An enhancement of the Fe magnetic moment at the interface (to 2.52 ${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$/atom) is predicted which, however, is significantly less than that found for the clean Fe(001) surface (2.95 ${\mathrm{\ensuremath{\mu}}}_{\mathit{B}}$). The role of the Ag overlayer in delocalizing the Fe surface states responsible for the increased surface magnetization and the effect on the single-particle spectra is described and discussed. The effect of the surface and interface on the contact hyperfine fields is evaluated: The (negative) core-polarization contribution is found to scale with the moment, but the valence contribution changes sign from negative in the interior to positive at the surface. The physical basis and the relationship of these results to the interpretation of M\"ossbauer-effect measurements of the hyperfine field are described.
TL;DR: In this article, the Curie temperature of the Fe 1-x Cu x alloys was investigated by X-ray diffraction and magnetization measurements and the mixed phase of bcc and fcc.
Abstract: High concentration Fe 1- x Cu x alloys have been obtained by rf sputtering technique and investigated by X-ray diffraction and magnetization measurements. The bcc phase is extended over the region with x =0–0.4, while the fcc phase with x =0.6–1.0. For x =0.4–0.6, we have the mixed phase of bcc and fcc. The lattice constant of bcc phase increases slightly and that of fcc phase decreases with increasing x . In the bcc alloys, the average magnetic moment decreases with increasing x and deviates upwards from the simple dilution law. In the fcc alloys, the magnetic moment also decreases with increasing x but it deviates downwards from the simple dilution law. The Curie temperature, T c , of the Fe 1- x Cu x alloys decreases abruptly with increasing x : T c is higher than 750 K for the bcc alloys, while it is lower than 320 K for the fcc alloys and become 0 K at about x =0.92.
Patent•
26 Nov 1984
TL;DR: In this paper, a marker for an electronic article surveillance system is disclosed comprising a body of magnetic material with retained stress and having a magnetic hysteresis loop with a large Barkhausen discontinuity such that, upon exposure of the marker to an external magnetic field whose field strength in the direction opposing the instantaneous magnetic polarization of the markers exceeds a predetermined threshold value, there results a regenerative reversal of the magnetic polarization.
Abstract: A marker for an electronic article surveillance system is disclosed comprising a body of magnetic material with retained stress and having a magnetic hysteresis loop with a large Barkhausen discontinuity such that, upon exposure of the marker to an external magnetic field whose field strength in the direction opposing the instantaneous magnetic polarization of the marker exceeds a predetermined threshold value, there results a regenerative reversal of the magnetic polarization of the marker An electronic article surveillance system and a method utilizing the marker are also disclosed Exciting the marker with a low frequency and low field strength, so long as the field strength exceeds the low threshold level for the marker, causes a regenerative reversal of magnetic polarity generating a harmonically rich pulse that is readily detected and easily distinguished
TL;DR: In this article, a linear system theory is used to model the magnetization process of a sediment using a convolution integral of geomagnetic field variation and a moment fixing function, which predicts that a field variation is deformed by filtering to be recorded in magnetization of sediments, and that the original field is deduced from the record of magnetization by deconvolution method.
Abstract: Magnetizing process of a sediment is formulated using a linear system theory. Remanent magnetization is represented as a convolution integral of geomagnetic field variation and a moment fixing function. The formulated model predicts that a field variation is deformed by filtering to be recorded in magnetization of sediments, and that the original field is deduced from the record of magnetization by a deconvolution method. Application of the model to the magnetization data of a core of shallow water sediment reveals that the remanent intensity variation may reflect the intensity reduction due to the cancellation of magnetic moments aligned in various directions rather than decrease in a field intensity. Width of magnetizing zone is inferred to be unexpectedly small from results of measurement of magnetization and laboratory experiments. The half fixing depths, at which a half of magnetic moments in a horizon is locked in, seem to cluster around 10cm or less.
TL;DR: In this article, Ferromagnetic resonance in a polished 0.047-cm-radius sphere of gallium-doped yttrium iron garnet is studied at 1.3 GHz in a magnetic field of 460 G.
Abstract: Ferromagnetic resonance in a polished 0.047-cm-radius sphere of gallium-doped yttrium iron garnet is studied at 1.3 GHz in a magnetic field of 460 G. A second-order Suhl instability is observed, owing to the nonlinear coupling of the precessing uniform magnetization with spin waves. This is detected by the onset of auto-oscillations of the magnetization. One of these modes with frequency \ensuremath{\approx}16 kHz corresponds to the lowest spherical dimensional resonance of a packet of spin waves of small wave vector and long lifetime (\ensuremath{\approx} ${10}^{3}$ cycles). From real-time signals, spectral analysis, and return maps this mode is found to display chaotic dynamics as the driving rf field is increased: thresholds for the onset of period-doubling bifurcations, chaos, and periodic windows. Some observed return maps bear resemblance to the two-dimensional area-preserving quadratic map of H\'enon. The system has several attractors and displays "solid-state turbulence," analogous to that in fluids.
TL;DR: In this paper, the authors focus on the magnetic field and magnetic isotope effects on the products of organic reactions and discuss reactions of radical pairs and examine the spin states of radical pair systems as archetypes.
Abstract: Publisher Summary This chapter focuses on the magnetic field and magnetic isotope effects on the products of organic reactions. The chapter discusses reactions of radical pairs and examines the spin states of radical pair systems as archetypes. The crucial condition for observation of magnetic field effects is a competition between two processes: one of the processes must be magnetic field dependent and the other is magnetic field independent. As for magnetic field effects, magnetic isotope effects are generally very small or negligible in homogeneous solution, but may become significant in microheterogeneous environments, such as micelles. The chapter illustrates an example of a magnetic isotope effect involving 17 O, occurring in the thermolysis of endoperoxides of aromatic compounds. The decomposition of certain endoperoxides produces singlet molecular oxygen and the yield of singlet oxygen is magnetic field dependent. Such effects have been observed in many different kinds of chemical systems, and are readily interpreted in terms of the well-established principles of chemically induced magnetic polarization.
TL;DR: In this article, the properties of NiMnSb and IrMnGa were studied by neutron diffraction and the results of these measurements are in accord with the occurrence of high atomic ordering in the first two compounds but point to high atomic disorder in the latter material.
TL;DR: In this article, the structural and magnetic behavior of selected metalloid (B,C) containing hexagonal and tetragonal rare earth-transition metal compounds and compound series was investigated.
TL;DR: In this article, the Brillouin-like function was used to obtain the s-d exchange constants in Zn 1−x Mn x Se : N o α = 0.26 eV, N o β = −1.31 eV.
TL;DR: In this paper, it was shown that when R is a magnetic ion, the compounds order antiferromagneticically and become superconducting at 3.5 K and 2.4 K respectively.
Journal Article•
TL;DR: The frequency of the long-lived induction signal in /sup 3/He-B depends on the time, and the rate of change of this frequency increases with increasing field gradient as discussed by the authors.
Abstract: The frequency of the ''long-lived'' induction signal in /sup 3/He-B depends on the time, and the rate of change of this frequency increases with increasing field gradient. Experiments confirm Fomin's theoretical explanation of this phenomenon, according to which a /sup 3/He-B sample in which a uniform magnetization precession is excited breaks up into two phases. In one, the magnetization is parallel to the field and does not precess; in the other, the magnetization precesses with a deflection angle of approximately 104/sup 0/.
TL;DR: In this paper, the saturation magnetization, uniaxial anisotropy, optical absorption α, Faraday rotation θF, and the Faraday ellipticity ψF of epitaxial garnet films of composition Y3−xBixFe5−yAlyO12 were investigated for x≤1.34 and y≤2.22.
Abstract: The saturation magnetization Ms, the uniaxial anisotropy Ku, the optical absorption α, the Faraday rotation θF, and the Faraday ellipticity ψF of epitaxial garnet films of composition Y3−xBixFe5−yAlyO12 have been investigated for x≤1.34 and y≤2.22. The temperature dependence of Ms and θF at λ=633 nm have been measured in the range 4.2 K≤T≤TC. Ku, TC, θF, and ψF reveal a linear dependence on the bismuth content. The dependence of θF and ψF on the aluminum concentration shows that both sublattices are involved and indicate that the magneto‐optical effects have to be ascribed to iron pair transitions. The magnitude of the growth‐induced anisotropy is essentially controlled by the supercooling ΔTs and increases linearly with ΔTs. The obtainable magnetic and magneto‐optical data for magneto‐optical applications are discussed and compared with those of garnet films exhibiting a compensation temperature.
TL;DR: In this article, the measurement and interpretation of magnetic hyperfine anomalies in electronic and muonic atoms is discussed. But the authors focus on the effects of the distribution of nuclear magnetization on the magnetic dipole hyperfine interaction.
Abstract: This study is concerned with the measurement and interpretation of magnetic hyperfine anomalies in electronic and muonic atoms ie effects of the distribution of nuclear magnetization on the magnetic dipole hyperfine interaction After a summary of the relevant theory and a review of experimental techniques, hyperfine anomaly results are discussed in terms of various nuclear models The use of the anomaly for yielding information about the origin of magnetic hyperfine interactions is outlined Experimental and theoretical hyperfine anomalies are tabulated
TL;DR: The rotation-induced saturation transfer in EPR spectra has been studied in pulse experiments using an electron spin-echo spectrometer supplied with a magnetic field modulation coil as mentioned in this paper.
TL;DR: In this paper, the magnetic ordering of polycrystalline samples of (Pr, Nd, Gd, Tb, Dy, Er)Ru2Si2 compounds was investigated in the temperature range between 1.8 and 293 K.