Showing papers on "Magnetization published in 1971"
TL;DR: In this paper, the saturation magnetization of very pure iron and nickel has been measured absolutely by a force method at room temperature, and the values are 217.6 and 55.1 emu/g (217.6 −1 kg −1 ) respectively.
Abstract: The saturation magnetizations of very pure iron and nickel have been measured absolutely by a force method at room temperature. The values are 217.6 and 55.1 emu/g (217.6 and 55.1 J T -1 kg -1 ) respectively. The theory and reliability of the force method are investigated and discussed. New measurements have also been made by a relative method on the same materials at temperatures ranging from 4 K to above the respective Curie temperatures of iron and nickel. Reduced magnetization, temperature data have been derived and are compared with those already available for face centred cubic cobalt.
406 citations
TL;DR: In this article, it was shown that the variable *, the conductivity-weighted, vertically averaged velocity is important in the generation of both local and large-scale electric currents.
Abstract: Motionally induced electric and magnetic fields are investigated in the sea, crust, and mantle for large-scale low-frequency oceanic flows. It is shown that three-dimensional flows generate large-scale horizontal electric currents not present in two-dimensional motions. The resulting induced magnetic fields penetrate into the mantle inducing there electric currents. The degree of mutual induction between the ocean and the mantle depends on the parameter δmL, the ratio of the electromagnetic skin depth of the mantle to the horizontal scale of the flow. For δmL≫1 there is little mutual induction whereas for δmL≪1 there is strong coupling between the ocean and the mantle. It is shown that the variable *, the conductivity-weighted, vertically averaged velocity is important in the generation of both local and large-scale electric currents. Expressions are derived showing that , the vertically averaged velocity, can be determined from measurements of the induced electric and magnetic fields at the sea floor. Several special cases are calculated illustrating the influences of the mantle, the conducting sediments, and the horizontal scales of the motion.
230 citations
TL;DR: In this article, it was shown that in YIG the magnetization in low fields is due to the same mechanisms for the whole temperature range to the Curie point, and that at a given temperature the magnetisation curves for different samples can be reduced to a single curve by taking into account the grain size.
Abstract: It is shown that in YIG the magnetization in low fields is due to the same mechanisms for the whole temperature range to the Curie point. At a given temperature the magnetization curves for different samples can be reduced to a single curve by taking into account the grain size. The interpretation is based on a model proposed earlier by Globus: the value of the reversible magnetization would be determined by the wall bulging, the value of the nonreversible magnetization by the wall displacement inside a spherical grain. For different temperatures a single reduced line is obtained by introducing the saturation magnetization and the effective anisotropy field, which is calculated from the susceptibility measured on a sample with single domain grains. So, it is possible to obtain a single magnetization curve which characterizes the composition.
228 citations
TL;DR: In this paper, the authors measured the variation in direction of the horizontal component of remanent magnetisation with depth in the sediments of the South basin of Windermere, England, and concluded that the sediment of freshwater lakes contain an accurate record of the directional variations of the magnetic field during the period of sedimentation and that these variations can provide a time scale in such materials.
171 citations
TL;DR: In this paper, a spectral description of a magnetic anomaly caused by a specific magnetic model is proposed, where the anomaly can be described in terms of wavelength, amplitude and phase, depending on the inclination of the magnetization and the strike of the symmetry axis.
Abstract: A spectral description allows the anomaly caused by a specific magnetic model to be described in terms of wavelength, amplitude and phase. For a two-dimensional symmetrical magnetization distribution related to ocean floor spreading, the phase is defined by the degree of asymmetry of the anomaly which depends on the inclination of the magnetization and on the strike of the symmetry axis.
140 citations
IBM1
TL;DR: In this article, a model involving head motion for self-consistently computing magnetic recording medium magnetization patterns is given, and the reduction in demagnetizing field due to the presence of the high-permeability head structure is included, as is record head removal, read head replacement, and computation of the readback voltage.
Abstract: A model involving head motion is given for self-consistently computing magnetic recording medium magnetization patterns. The reduction in demagnetizing field due to the presence of the high-permeability head structure is included, as is record head removal, read head replacement, and computation of the readback voltage. The model is capable of handling an arbitrary record current waveform. Optimum record-current amplitude for nonreturn to zero (NRZ) digital recording is first determined, and then single-, double-, and quadruple-transition computations are performed using two different values of hysteresis loop squareness M_{r}/M_{s} and both linear and exponential current reversals. Results are primarily for the Karlquist fringe field, but the recording properties of a head exhibiting regions in which the fringe field reverses sign are also briefly investigated.
101 citations
TL;DR: In this paper, the nuclear quadrupole coupling constants and isomer shifts of 57Fe in the spinels ZnFe2O4 and CdFe 2O4 were measured using the Mossbauer effect.
Abstract: The nuclear quadrupole coupling constants and isomer shifts of 57Fe in the spinels ZnFe2O4 and CdFe2O4 were measured using the Mossbauer effect. The signs of the quadrupole coupling constants were determined from spectra which were taken in an applied magnetic field. The sign is negative in both spinels. The isomer shifts and Fe–O distances indicate that Fe3+ in ZnFe2O4 is somewhat more covalently bonded than in CdFe2O4. The external field gradients at the Fe3+ positions can be interpreted in terms of the ionic point‐multipole model modified by some charge transfer between oxygen and the cations. The point charge contribution to the field gradient is positive in case of ZnFe2O4 and nearly zero in case of CdFe2O4; the predominant contribution is due to the electric dipole moments of the oxygen ions and is negative. The dipole polarizability of the oxygen ion which gave the best fit is αD = 0.8 A3. The effect of charge transfer on the ionic field gradient is small.
93 citations
TL;DR: The reported orientation of retinal rods in a homogeneous magnetic field can be explained by the magnetic anisotropy of oriented molecules in the disc membranes of the rods.
Abstract: The reported orientation of retinal rods in a homogeneous magnetic field can be explained by the magnetic anisotropy of oriented molecules in the disc membranes of the rods.
The energy of a single rod as a function of orientation in the magnetic field, the time required for alingment of the rod in a viscous medium, and the fluctuations of orientation are calculated. Arguments that rhodopsin is the constituent responsible for the effect are given. The possibility of orientation due to inhomogeneity of the magnetic field is ruled out. The application of magnetic anisotropy as an experimental tool in biology is indicated.
81 citations
TL;DR: In this article, it was shown that a magnetic field of 2 kilogauss in the basal plane of hematite can significantly increase the attenuation and velocities of ultrasonic wave propagation.
Abstract: Domain wall-stress interaction causes pronounced increases in attenuation and decreases in the velocities of ultrasonic (30 MHz) waves in hematite at 298°K relative to the values in a saturating magnetic field. For compressional modes, these effects are about 10 db/cm in attenuation and less than 1% in velocity and may be eliminated by the application of a magnetic field of 2 kilogauss in the basal (c) plane. At zero applied field, it was not possible to propagate shear waves in the single crystal; as the field is varied from 2 to 4 kG, the attenuation decreases by about 30 db/cm, and the velocities increase by as much as 10%. These data are consistent with the fact that hematite exhibits weak ferromagnetism at room temperature, with the spins largely contained in the c plane. The large fields needed to saturate the crystal indicate the presence of a hard component of magnetization. These magnetoelastic interactions can also be eliminated by cooling through the Morin temperature (TM=261°K), below which point the spins are aligned parallel to the trigonal c axis and the weak ferromagnetism vanishes. At low pressures, TM increases by 3.6°K/kb and occurs at 298°K near 30 kb. The results of this study have important consequences for ultrasonic studies of the elastic properties of third-transition metal oxides, for static compression experiments on these materials, and for studies of phase transitions in solids.
75 citations
TL;DR: In this article, the surface and bulk critical exponents of NiO were determined using the molecular field model and qualitative scaling arguments, and it was shown that the surface exchange interaction is weaker than the bulk exchange interaction.
74 citations
TL;DR: In this paper, the static magnetization of dilute Cu(Mn) alloys with Mn concentrations between 4.2 and 106 ppm has been measured between 10 mK and 0.4 K in fields between 1 and 200 Oe.
Abstract: The static magnetization of dilute Cu(Mn) alloys with Mn concentrations between 4.2 and 106 ppm has been measured between 10 mK and 0.4 K in fields between 1 and 200 Oe. Magnetic ordering is observed and attributed to impurity-impurity interactions. However, a concentration-independent Weiss constant and a decreasing moment per impurity in the low-field, low-temperature limit are evidence for the increasing importance of single-impurity effects with characteristic temperatureT
k
∼ 2 mK.
TL;DR: In this paper, a new superparamagnetic threshold for haematite using magnetic measurements on synthetic hahematite particles, prepared by a modification of the technique of Kundig et al.
Abstract: HAEMATITE (α−Fe2O3) is an important carrier of natural remanence magnetization (NRM) in sedimentary rocks (such as red sandstones and shales, oceanic red clays) as well as in some volcanic rocks (such as highly oxidized basalts, ignim-brites) and monomineralic rocks (cassiterite, for example). To be useful to the palaeomagnetist, however, such haematite particles should preserve the integrity of the intensity and direction of their NRM over geological time-scales. One of the primary requirements, therefore, is that the grain size should fall between two size thresholds; the lower of these two is the superparamagnetic threshold (ds.p.) and the higher size corresponds to the multi-domain threshold (dm.p.). The importance of the superparamagnetic threshold in palaeomagnetism was illustrated by Creer1 in his study of the Keuper marl. He showed that the principal reason for the instability of NRM in this red rock was due to the haematite grains being smaller than ds.p. ; thus the thermal energy, kT, at room temperature was larger than the stabilizing magnetic anisotropy energy, vK, where volume v=πd 3 /6 and anisotropy energy per unit volume = K. Creer studied2 the variation of magnetization with grain size using synthetic haematite derived from dehydrated goethite. One concludes from his data that ds.p.,the superparamagnetic threshold in haematite, is less than 100 A since even at d=100 A, haematite exhibited field-dependent susceptibility. Strangway et al.3 used dehydrated natural goethite to establish the value of ds.p. and found it to be 5000 A, vastly different from the value of <100 A, concluded by us from Creer's work2. Kundig et al.4 prepared synthetic haematite in commercially available silica gel matrix and studied the onset of superparamagnetism using Mossbauer effect. Since these samples are not likely to be contaminated by goethite (goethite, in spite of being an antiferromagnetic compound, can possess weak ferromagnetism due to internal defects)3,5, the Moss-bauer-derived ds.p. of 150 A ought to be more reliable. Kundig's preparation technique was to soak silica gel samples with an inorganic iron salt solution and then heat the samples to prepare the haematite grains. This process leads to “clumping” and a large distribution of grain sizes and Dunlop (in the press) has pointed out the fact that Mossbauer effect measurements lead to the determination of the product (vK)s.p. and not vs.p. uniquely. Thus one should regard the Mossbauer derived ds.p. of 150 A as tentative, until purely magnetic measurements can establish uniquely the superparamagnetic threshold. In what follows we present a new ds.p. value using magnetic measurements on synthetic haematite particles, prepared by a modification of the technique of Kundig et al. leading to a much narrower size distribution.
TL;DR: In this paper, the distribution of the internal magnetic fields and its temperature dependence of Fe 57 nuclei in fcc iron-nickel alloys with composition ranging from 31.8 to 65.6 at.
Abstract: Distribution of the internal magnetic fields and its temperature dependence of Fe 57 nuclei in fcc iron-nickel alloys with composition ranging from 31.8 to 65.6 at.% Ni have been measured by Mossbauer effect from 88°K to above Curie temperature. Distribution of the internal field has been determined from the observed Mossbauer spectra and temperature variation of the distribution has been explained by using the molecular field model which shows that iron moments on which weaker exchange field is acting from the neighbouring moments decrease more rapidly with increasing temperature than those on which stronger exchange field is acting. Distribution of the internal magnetic field has been correlated to the distribution of the exchange field. Temperature dependence of saturation magnetization and other magnetic properties of iron-nickel alloys has been discussed on the basis of local fluctuation of the exchange field.
TL;DR: In this article, the magnetic moment per formular unit was measured of single crystal spheres of Y, Ce, Pr, Nd and SmCo5 compounds and the anisotropy constants were estimated from the K1 and K2 vs temperature curves.
Abstract: Magnetization measurements of single crystal spheres of Y, Ce, Pr, Nd and SmCo5 compounds yield the magnetic moment per formular unit 7.9, 6.6, 10.4, 10.4 and 7.7 µB, respectively. The anisotropy constants K1 (0) and K2 (0) at 0 °K estimated from the K1 and K2 vs temperature curves measured are 6.5 and ~ 0, 5.5 and ~ 0, - 7 and 18, - 40 and 19, 10.5 and ~ 0 (x 107 ergs.cm-3) for the above compounds, respectively. Linear variation of K1 (0) and K2 (0) with x obtained in Y1-xNdxCo5 gives evidence in support of single ion model.
TL;DR: In this article, the Fourier transforms of the sampled continuous functions are used in an analysis which leads to a system of linear equations involving terms in density, magnetization, and calculated finite Fourier series coefficients.
Abstract: The relationship between the gravitational and magnetic potentials caused by a uniform distribution of mass and magnetization may be used to obtain independent information about these physical properties. The general relationship in the frequency domain between the Fourier transforms of the gravity and magnetic anomaly fields is established through the Poisson theorem. The discrete Fourier transforms of the sampled continuous functions are used in an analysis which leads to a system of linear equations involving terms in density, magnetization, and calculated finite Fourier‐series coefficients. A least squares solution of the system yields the three components of the total magnetization vector divided by the density. From these results, the direction of total magnetization and the minimum of the Koenigsberger ratio Q can be determined uniquely. The remanent magnetization direction and certain other information can be derived for special cases in which the value of one or more of the physical property term...
TL;DR: In this article, it was shown that a magnetic system consisting of ions with spin S = 1, which have a large uniaxial anisotropy energy D and interact with neighbours by means of an exchange interaction J much smaller than D, shows an interesting spin ordering with a non-vanishing transverse component in an external magnetic field such that μBH ∼ D. The phase transition to this state is shown to be of the second order and the transition temperature is determined as a function of the magnetic field.
TL;DR: In this paper, the mechanism of magnetic processes is attributed completely to the thermal activation of moment reversal and not to interactions, and the inclusion of particle interactions in a consistent manner through the thermodynamic and kinetic formalism.
Abstract: Thermodynamic and kinetic considerations applied to an assembly of single domain particles have resulted in a single set of equations that describe such diverse processes as hysteresis, time effects, thermoremanent magnetization, and anhysteretic magnetization. An important feature of this work is the inclusion of particle interactions in a consistent manner through the thermodynamic and kinetic formalism. The mechanism of magnetic processes is attributed completely to the thermal activation of moment reversal and not to interactions. Interactions, however, substantially modify the magnitude of the effects.
TL;DR: In this paper, the degree of polarization of electrons emitted from the neighborhood of the Fermi level was found to be + 54, + 21, and + 15% for Fe, Co, and Ni, respectively.
Abstract: This experiment shows that photoelectrons from $3d$ ferromagnets exhibit a large spin polarization, which is in contrast to earlier investigations. The degree of polarization of electrons emitted from the neighborhood of the Fermi level was found to be + 54%, + 21%, and + 15% for Fe, Co, and Ni, respectively. The preferential direction of the magnetic moment is parallel to the magnetization, and this provides strong evidence against the applicability of the Stoner-Wohlfarth-Slater band theory for the interpretation of photoemission data. On introducing disorder in the lattice by depositing thin films onto cold substrates, the spin polarization decreases; for Fe and Ni the decrease scales with the number of Bohr magnetons per atom.
TL;DR: In this article, the magnetic properties of the single crystals of Cr 2-δ Te 3, prepared by the chemical transport method, were investigated, and it was shown that the Bohr magneton numbers per Cr-ion are 2.0 2 and 1.9 6 µ B for Cr 1.96 Te 3 and Cr 0.98 Te 3 respectively, in contradiction to those expected from the magnetic susceptibility.
Abstract: The magnetic transitions of the Cr-Te system has not been explained by a suitable model. Therefore, the magnetic properties of the single crystals of Cr 2-δ Te 3 , prepared by the chemical transport method, were investigated. From the measurement of the magnetic susceptibility above room temperature S =3.0 8 /2 per Cr-ion is obtained, which is coincident with the spin only value of Cr 3+ ion and a ferromagnetic transition is found to be expected. While, from the extrapolated magnetization value to 0 K, the Bohr magneton numbers per Cr-ion are 2.0 2 and 1.9 6 µ B for Cr 1.96 Te 3 and Cr 1.98 Te 3 , respectively, and these values are in contradiction to those expected from the magnetic susceptibility. Qualitative considerations about these anomalous magnetic transition are given.
TL;DR: In this article, the authors studied polycrystalline thin films of MnAlGe formed on various substrates by getter sputtering, and the optimum substrate temperature to obtain films with uniform magnetic properties was 500°C.
Abstract: MnAlGe is a uniaxial ferromagnetic compound with a saturation 4πMs of 3600 G, and Curie temperature of 245°C. We have studied polycrystalline thin films of this compound formed on various substrates by getter sputtering. The optimum substrate temperature to obtain films with uniform magnetic properties was 500°C. Films prepared at this temperature have a substantial component of magnetization normal to the plane of the substrate, and a coercive force of approximately 2000 Oe. Information was written into films approximately 700‐A thick by Curie point writing or with a fine permanent magnet wire, and read with good optical contrast by means of the polar Faraday effect. The relatively low Curie temperature is advantageous in reducing the power required for Curie point writing for magneto‐optic memory or holographic applications.
TL;DR: In this article, the temperature dependence of the magnetic susceptibility of deoxymyoglobin and deoxyhemoglobin were measured in different temperatures ranging from 2.0 to 77°K.
TL;DR: In this article, the similarity of the ordered magnetic structures of orthorhombic MnAs (stable at high pressure) and orthor hombic NMAs0.92P0.08 has been confirmed using neutron diffraction.
Abstract: The similarity of the ordered magnetic structures of orthorhombic MnAs (stable at high pressure) and orthorhombic MnAs0.92P0.08 has been confirmed using neutron diffraction. Below the magnetic ordering temperature, Tc, a canted spin structure is found for both materials. Neutron diffraction measurements from magnetically ordered and disordered temperature regions show that in these materials the Mn magnetic moment varies with the volume of the Mn atom. The variation of the magnitude of the Mn magnetic moment is explained using the relation between Pauling valence and magnetic moment introduced by Mori and Mitsui. The results are in disagreement with the currently accepted interpretation of the susceptibility data.
TL;DR: The magnetic properties of a single crystal of almost pure Ulvospinel Fe 2.05 Ti 0.95 O 4.00 have been investigated by neutron diffraction and magnetic studies.
Abstract: Magnetic properties of a single crystal of almost pure Ulvospinel Fe 2.05 Ti 0.95 O 4.00 have been investigated by neutron diffraction and magnetic studies. Fe 2 TiO 4 is a perfect inverse spinel with oxygen parameter of u =0.386±0.001 at room temperature. The crystal becomes weakly ferromagnetic below 142°K. The magnetic structure is of the Neel type with the sublattice magnetic moments of 4.2±0.2µ B on both octahedral and tetrahedral sites at 4.2°K. The moment on the octahedral site decreases with increasing temperature faster than that on the tetrahedral site. The spontaneous weak ferromagnetic moment is induced in one of the direction perpendicular to spins. The spins tend to orient to the direction of the field, only when the magnetic field is applied in the [100] direction. The crystal is suggested to distort tetragonally at low temperatures with the spin along the long axis. The average \bar u parameter at 4.2°K is also 0.386±0.001.
TL;DR: In this paper, the authors studied the kinetics of the spin 4 Ising chain for a class of master equations describing transitions in the spin system owing to interactions with a heat bath.
TL;DR: In this paper, annealing at 1000 K is performed on the trivalent ligands of C14 ErFeAl and C15 ErFe2 to ErAl2 and the results show that the ligands become nonmagnetic toward the Al-rich phase boundary.
Abstract: Specimens annealed at 1000 K are of C15 type from ErFe2 to Er0.333Fe0.425Al0.242, of C14 type from Er0.333Fe0.412Al0.255 to Er0.333Fe0.237Al0.430, and of C15 type from Er0.333Fe0.222Al0.445 to ErAl2. Magnetic investigations in the paramagnetic and ordered region show evidence for electron transfer to Fe from the trivalent ligands to the extent that Fe becomes nonmagnetic toward the Al‐rich phase boundary of C14 ErFeAl. The materials order ferromagnetically on rare‐earth sites, while Fe aligns antiparallel to the lanthanide. The saturation mechanism, however, is complex. Domain‐wall effects, anisotropy, and the development of disordered magnetic components may be responsible for depressions in the saturation values of certain concentrations, stepwise increases of magnetization with field, and almost linear increases in magnetic moment in higher fields (10–47 kOe).
TL;DR: The magnetic properties of crystalline rock and fine samples returned by the Apollo 12 mission have been measured as discussed by the authors, and it has been shown that the fine samples contain at least 0.7% by mass of native iron, mainly in the superparamagnetic form at room temperature.
Abstract: The magnetic properties of crystalline rock and fines returned by the Apollo 12 mission have been measured. The fines contain at least 0.7% by mass of native iron, mainly in the super-paramagnetic form at room temperature. Native iron is present in the crystalline rock but in a much lower concentration. The paramagnetic minerals, ilmenite and ulvospinel, are present. Some evidence has been obtained that magnetite is present in the crystalline rock, less than 0.02% by mass. It has not yet been established whether it is indigenous to the rock. Two samples exhibit a change in n.r.m. at low temperature consistent with this n.r.m. being carried by magnetite, but these investigations are not yet complete. The crystalline rocks possess an n.r.m. of intermediate stability: there is evidence for two components of magnetization, a weak and rather stable one, and a less stable but stronger component. The former indicates the presence of a magnetic field on the moon at the time of formation of the rocks. An external origin seems unlikely: thus the Moon possessed a magnetic field of internal origin 3400 Ma section ago which has since decayed.
TL;DR: Amorphous quasibinary alloys having the composition (Fe1−xMnx)0.75P0.15C0.10, where 0.5≤x≤1.0, were synthesized by rapid quenching from the liquid state.
Abstract: Amorphous quasibinary alloys having the composition (Fe1−xMnx)0.75P0.15C0.10, where 0.0≤x≤1.0, were synthesized by rapid quenching from the liquid state. Their magnetic behavior was characterized by measurements of the magnetization as a function of temperature in the range 4.2°–300°K, and in fields ranging from 1 to 8.5 kOe. The iron‐rich alloys with 0.0≤x≤0.4 are ferromagnetic: the magnetic moment at 0°K decreases linearly from 2.07 μB/Fe atom in Fe0.75P0.15C0.10 to 0.22 μB/(Fe, Mn) atom in (Fe0.6‐Mn0.4)0.75P0.15C0.10. Judging from the large values of the parameter qc/qs, where qc and qs are the number per mole of magnetic carriers in the paramagnetic and ferromagnetic states, respectively, and also from the nonsaturating behavior of magnetization with field at 4.2°K, it appears that the ferromagnetism in these alloys may be of the itinerant kind. Alloys having 0.5≤x≤1.0 possess considerably more complex magnetic structures. They are characterized by a peak in the magnetization curve at temperatures bet...
TL;DR: For annealed, low carbon content materials in a small magnetic field, the magnetization-stress curves are unsymmetrical with respect to tension and compression, and the asymmetry becomes less pronounced both for an increase in residual internal stress and for increase in carbon content until, for cold-worked, high carbon content material, curves are obtained that are sensibly symmetrical.
Abstract: The variation of magnetization produced by the simultaneous application of magnetic fields and stresses (both compressive and tensile) has been studied for a range of iron-carbon alloys that have been subjected to various metallurgical treatments. For annealed, low carbon content materials in a small magnetic field, the magnetization-stress curves are unsymmetrical with respect to tension and compression. In the applied fields and stresses used, the asymmetry becomes less pronounced both for increase in residual internal stress and for increase in carbon content until, for cold-worked, high carbon content materials, curves are obtained that are sensibly symmetrical. Up to now, two mechanisms have been used to explain the experimentally observed changes in magnetization, namely, that of stress-induced pressure p acting on 90° domain walls and that of large-scale changes in domain structure due to stress. It is demonstrated that these two mechanisms alone cannot account for the present observations. However, qualitative agreement is obtained over the whole range of alloys when account is taken of a third mechanism, that of stress-induced changes in the opposition term that must be in balance with p for domain wall equilibrium.
TL;DR: In this paper, the authors present measurements of thermoelectric power for nickel and cobalt dilute alloys with d transition elements in two temperature ranges: from 1.3 to 4.2 K and from 77 to 300 K. The results of the measurements at room temperature in a two-band conduction model and deduce the thermopowers associated with the matrix (Smσ) and with the impurities (Soσ) in each sub-band σ.
Abstract: We present new measurements of thermoelectric power for nickel and cobalt dilute alloys with d transition elements in two temperature ranges: from 1.3 to 4.2 K and from 77 to 300 K. We analyse the measurements at room temperature in a two-band conduction model and deduce the thermopowers associated with the matrix (Smσ) and with the impurities (Soσ) in each sub-band σ. The results obtained for the impurity thermoelectric power confirm the model of electronic structure suggested for this alloy from magnetization and resistivity measurements; this model is characterized by the occurrence of a virtual bound state supward arrowdupward arrow at the Fermi level when the charge difference between the matrix and the impurity is large enough. From the values of impurity thermoelectric power in the supward arrow sub-band, we deduce the position and the width of the virtual bound state.
TL;DR: In this paper, theoretical results for magnetization as a function of pulse spacing τ are given for cases where the Bloch equations apply, and compared with experiments, suggesting a simple method of rapid signal accumulation when T2*
Abstract: Several pulsed NMR experiments using rapidly repeating pulse sequences are described. Theoretical results for magnetization as a function of pulse spacing τ are given for cases where the Bloch equations apply, and compared with experiments. These results suggest a simple method of rapid signal accumulation when T2*