Showing papers in "Journal of the Physical Society of Japan in 1966"
TL;DR: In this article, the linear response theory was used to describe the quantum-mechanical treatment of fine metallic particles with a peak optical absorption around the frequency of the plasma mode and the absorption is broadened by coupling of the plasmas oscillation with the individual electronic states which are quantized in discrete levels.
Abstract: Fine metallic particles exhibit a peak of optical absorption around the frequency of the plasma mode. The absorption is broadened by coupling of the plasma oscillation with the individual electronic states which are quantized in discrete levels. Thus the broadening should not be interpreted as the resistance of free electrons scattered at the surfaces of particles. The quantum-mechanical treatment is described here on the basis of the linear response theory. Existent experimental data are discussed briefly.
536 citations
TL;DR: A multiply twinned particle model is proposed by the present author, and the appearance of the 111 spots and the dark field image contrasts can satisfactorily be explained by this model.
Abstract: The orientation and structure of gold particles formed by evaporation on rocksalt cleaved in ultrahigh vacuum have been studied at various stages of the nucleation and growth process. Besides four 200 and twenty-four 220 spots which indicate the presence of the (001) orientation and (111) orientation respectively, twenty-four abnormal 111 spots have been observed in electron diffraction patterns taken at earlier stages of growth, and various unusual contrasts have been observed in dark field electron micrographs using one of 111 spots. A multiply twinned particle model is proposed by the present author, and the appearance of the 111 spots and the dark field image contrasts can satisfactorily be explained by this model. With increasing thickness particles with the (111) orientation and without the multiple twinning exclusively grow up, while multiply twinned particles and those with the (001) orientation seem to stop their growth; and a continuous gold film with the (111) fibrous structure is formed at a t...
465 citations
TL;DR: In this paper, the Schrodinger equation for a hypothetical two-dimensional hydrogen atom was used to solve the allowed and forbidden direct interband transitions in extremely anisotropic semiconductors, and the absorption intensities in the discrete, quasi-continuous, and continuous spectral regions were calculated.
Abstract: By using the effective-mass theory for exciton, the allowed and forbidden direct interband transitions in extremely anisotropic semiconductors are discussed. In this case, the problem is reduced to solving the Schrodinger equation for a hypothetical two-dimensional hydrogen atom. The bound and unbound solutions of the equation are obtained, and the absorption intensities in the discrete, quasi-continuous, and continuous spectral regions are calculated. It is shown that, in the allowed transitions, a small peak may appear just above the absorption edge because of the Coulomb interaction between an excited electron and a hole. This result is compared with the experimental curves of the absorption in layer-type semiconductors, CaS, GaSe, and GaTe.
365 citations
TL;DR: In this paper, the frequency of lattice vibrations around the imperfection which give rise to the level splitting of degenerate excited states are classified into active and potentially active modes according as they cause the absorption band to split or not.
Abstract: Possible patterns of vibration-induced splitting in the absorption band of localized electrons in solid are investigated within the Condon approximation. The modes of lattice vibrations around the imperfection which give rise to the level splitting of degenerate excited states are classified into active and potentially active modes according as they cause the absorption band to split or not. The result is applied to the analysis of the absorption bands of Tl + - like ions in alkali halides. One can explain the triplet structure of the C band and the doublet structure of the A band with its temperature sensitive asymmetry, by introducing the coupling constant c between the p -electron and the trigonal lattice vibrations as a single adjustable parameter. The dependences of c upon the host alkali halide and on the charge of the impurity ion are explained by a point-charge plus point-dipole model for the neighboring halide ions.
355 citations
TL;DR: In this article, the Gaussian expansion method for the evaluation of molecular integrals is described, which can be applied to integrals over any other functions as long as the functions can be expressed in terms of Gaussian type functions.
Abstract: The Gaussian-expansion method for the evaluation of molecular integrals is described. The molecular integrals over the Slater-type functions are chosen as numerical examples, but the method can be applied to integrals over any other functions as long as the functions can duly be expressed in terms of Gaussian-type functions. A fairly detailed description is presented of the mathematical analysis with the purpose of facilitating the computer coding.
209 citations
TL;DR: In this article, the band structure of ferromagnetic iron is calculated by the Green's function method and the crystal potential is determined self-consistently for both spin-up and spin-down electrons, respectively.
Abstract: The band structure of ferromagnetic iron is calculated by the Green's function method. The crystal potential is determined self-consistently for both spin-up and spin-down electrons, respectively. The theoretical results are compared with experimental results: the electronic specific heat, the magnetoresistance, de Haas-van Alphen effect and the scattering form factors. The agreement between the seems to be satisfactory.
194 citations
TL;DR: In this article, the method of least squares is used to obtain approximate expansions of Slater-type orbitals in terms of Gaussian type orbitals, which are good enough to use in quantum mechenical calculations of molecules.
Abstract: The details of the method of least squares for obtaining approximate expansions of Slater-type orbitals in terms of Gaussian type orbitals are described. Such Gaussian expansions are given for the 1 s , 2 s , 2 p , 3 s , 3 p and 3 d Slater-type orbitals. These expansions will be good enough to use in the quantum mechenical calculations of molecules.
177 citations
TL;DR: In this article, the authors proposed a possible form of interaction between radiation and paramagnetic ion pair, which is discussed and an order of magnitude argument is given to support the proposed mechanism.
Abstract: Earlier experimental work (J. Ferguson, H.J. Guggenheim and Y. Tanabe, J. appl. Phys. 36 (1965) 1046, Phys. Rev. Letters 14 (1965) 737) on the Mn pair spectrum of KZnF 3 :Mn and the spectrum of KMnF 3 has been extended. The narrow bands of KMnF 3 and RbMnF 3 have been assigned and their abnormally high intensities established. The transition is an electric dipole one and oscillator strength (∼9.5×10 -7 for the 4000 A absorption) is temperature independent, corresponding to an allowed transition. The experimentally observed features of the pair absorption suggest a possible form of interaction between radiation and paramagnetic ion pair. The origin of this interaction is discussed and an order of magnitude argument is given to support the proposed mechanism. Related problems such as exchange interaction in excited states and the spectra of the concentrated materials are also considered.
174 citations
TL;DR: In this article, the antiferromagnetism of polycrystalline and single crystal samples of disordered Fe-Mn alloys containing between 20 to 50 at% Mn was investigated by means of a magnetic balance, a sensitive torque magnetometer and neutron diffraction.
Abstract: The antiferromagnetism of polycrystalline and single crystal samples of disordered γ Fe-Mn alloys containing between 20 to 50 at% Mn was investigated by means of a magnetic balance, a sensitive torque magnetometer and neutron diffraction. The alloys with 20 to 27 at% Mn exhibited e ↔γ trans-formation in the same temperature range as the magnetic transformation. The relation between the magnetic and the crystallographic transformations was investigated and a phase diagram of Fe-Mn alloys in this composition region was obtained. A neutron diffraction study of single crystal samples confirmed the generalized antiferromagnetic spin structure proposed by the powder neutron diffraction study of Kouvel and Kasper. The torque measurements, made on single crystals which had been cooled through the Neel point in a strong magnetic field, indicated that the spin structure is intrinsically cubic, the spins on the four sublattices being directed toward the different cube diagonals. The results are discussed from the vi...
159 citations
TL;DR: In this paper, a new diffusion mechanism is proposed to interpret the remarkable deviation from the Einstein relation observed in the diffusion of silver ions in the high temperature forms of Ag 2 S and others.
Abstract: A new diffusion mechanism is suggested to interpret the remarkable deviation from the Einstein relation observed in the diffusion of silver ions in the high temperature forms of Ag 2 S and others. The essential feature of the proposed mechanism lies in admitting the cooperative jumps of two or more ions.
147 citations
TL;DR: In this paper, a spin echo amplitude for a spin system consisting of one nuclear species of spin I with a large Zeeman energy and a small quadrupole interaction has been calculated for the case the excitation is carried out by two succeeding arbitrary rf pulses.
Abstract: A spin echo amplitude for a spin system consisting of one nuclear species of spin I with a large Zeeman energy and a small quadrupole interaction has been calculated for the case the excitation is carried out by two succeeding arbitrary rf pulses. The spin echo amplitude shows an oscillatory behavior which depends on the time interval between the first and the second pulses. The relation between this fundamental modulation period and the separation of the multiplet of steady state NMR absorption signal is derived. The possibility of observing multiple spin echoes is discussed and the modulation periods of these multiple echoes are calculated. These results showed satisfactory agreement with the experimental results observed on boron nuclei in ferromagnetic Fe 2 B and MnB and on manganese nuclei in ferromagnetic MnB.
TL;DR: In this article, a systematic numerical study of the unsteady viscous incompressible fluid flow past a circular cylinder is reported and the range of the Reynolds number considered is 1 to 100.
Abstract: A systematic numerical study of the unsteady viscous incompressible fluid flow past a circular cylinder is reported. The range of the Reynolds number considered is 1 to 100. The steady state solutions could be obtained at the Reynolds numer R =10, 20, 30, 40, 50 as the limit of the unsteady state solutions. The numerical results are compared with those for the steady problem and they are found to be in agreement. Dependence of the flow pattern, vorticity distribution, pressure distribution and the drag are shown on the Reynolds number and the time.
TL;DR: In this article, a micromagnetic calculation was made in order to estimate the width of the stripe domains in a magnetic thin film with a perpendicular anisotropy, which drives the magnetization out of the plane.
Abstract: A micromagnetic calculation was made in order to estimate the width of the stripe domains in a magnetic thin film with a perpendicular anisotropy, which drives the magnetization out of the plane. The rotation of spins from the average magnetization, not only out of plane (similar to the µ * correction) but also in the plane (similar lo the closure domain), was taken into consideration. The rotating angles in both senses were assumed to be functions of the depth from the film surface and of the position across the stripe domain. They were determined so as to satisfy a set of Euler's equations, and solved numerically and also semi-analytically. The results are in good agreement with the experiments by Saito et al. .
TL;DR: In this paper, Mossbauer measurements were made on fine particles of antiferromagnetic α-FeOOH with various particle sizes to examine the spectra in fluctuating fields produced by the relaxation of electron spins.
Abstract: Mossbauer measurements were made on fine particles of antiferromagnetic α-FeOOH with various particle sizes to examine the Mossbauer spectra in fluctuating fields produced by the relaxation of electron spins. In ultra fine samples, the collapse of the internal field due to superparamagnetism was observed. The critical volume at 294°K was found to be 3×10 -17 cm 3 and the critical temperature for the sample of 1×10 -17 cm 3 to be 210°K. The effective anisotropy constant was estimated to be of the order of 10 4 erg/cm 3 . The transitional patterns from the ordinary magnetic splitting (6-line) to the superparamagnetic doublet are discussed and the assignment of the doublet is attempted in comparison with Blume's prediction.
TL;DR: In this article, single crystal films of γ-Fe 2 O 3 were epitaxially grown on a (100) surface of MgO by the halidedecomposition method.
Abstract: Single crystal films of γ-Fe 2 O 3 were epitaxially grown on a (100) surface of MgO by the halide-decomposition method. Chemical analysis, electrical conductivity and, optical absorption measurements showed that the crystals contain no ferrous ions. X-ray diffraction assigned a cubic spinel structure and ruled out the presence of ordering of cation vacancies. Magnetization measurement and ferromagnetic resonance experiments were performed on these films which revealed the value of saturation magnetization and the anisotropy constants. The effective Bohr magneton number per iron atom was determined to be 1.45 at 0°K, which is considerably larger than that expected from Neel's theory. The Curie temperature is 743°K, which is lower than that found in ordinary γ-Fe 2 O 3 powder. These results conclude that the vacancies at 16 d sites are randomly distributed and nearly twenty percent of the total vacancies occupy 8 a sites.
TL;DR: In this article, a relativistic generalization of the Green's function method for the energy-band calculation is presented, where the wave function within the atomic spheres is expanded in terms of four-component spherical waves.
Abstract: A relativistic generalization of the Green's function method for the energy-band calculation is presented. The wave function within the atomic spheres is expanded in terms of four-component spherical waves. The resulting expression which gives the relationship between E and k is very similar to the nonrelativistic one. Matrix elements between the spherical waves can be easily computed provided structure constants used in the nonrelativistic calculations are available.
TL;DR: In this article, the electrical conductivity, the magnetoresistance, the Hall coefficient and the thermoelectric power of single crystal graphite are theoretically calculated as functions of the temperature and magnetic field intensity in the region where lattice scattering is dominant.
Abstract: The electrical conductivity, the magnetoresistance, the Hall coefficient and the thermoelectric power of single crystal graphite are theoretically calculated as functions of the temperature and magnetic field intensity in the region where lattice scattering is dominant. The values of the electron-phonon coupling constants which fit the theory to the experimental results best are: D 1 =16.2 eV and D 2 =3.73 eV. Here D 1 and D 2 denote the coupling constants related with the in-plane vibration (mode 1) and the out-of-plane vibration (mode 2) respectively. The field and temperature dependence of the magnetoresistance is in qualitative agreement with the measurements by Soule, while the calculated Hall coefficient has the opposite signs to the experimental results. These discrepancies may be closely related with the neglect of the trigonal symmetry of the bands (γ 3 ). The thermoelectric power calculated is positive and increases monotonously with increasing temperature, but there is no available data to be c...
NEC1
TL;DR: For the double point groups O, O h, T d, D 4 h, D 4 v, C 4 v, D 3 d, C 3 v, and C 2 v, the basis functions tabulated are orthogonal to one another and diagonal with respect to the total angular momentum j = l + s.
Abstract: Irreducible representations and basis functions are given for the double point groups O , O h , T d , D 4 h , C 4 v , D 3 d , C 3 v , and C 2 v . The basis functions tabulated are orthogonal to one another and diagonal with respect to the total angular momentum j = l + s .
TL;DR: The temperature dependence of the Mossbauer spectra can be explained qualitatively on the basis of the simple model of a motional narrowing phenomenon as discussed by the authors, which can be found in the case of FeV 2 O 4.
Abstract: Mossbauer spectra of FeCr 2 O 4 and FeV 2 O 4 , which undergo the cubic-to-tetragonal transition at 135°K and 140°K respectively, have been measured in the temperature range from liquid nitrogen to room temperature. Quadropole splittings have been observed even above the distortion temperature. Each line of the Mossbauer spectra becomes broadest at the transition temperature. These temperature dependence of the Mossbauer spectra can be explained qualitatively on the basis of the simple model of a motional narrowing phenomenon.
TL;DR: In this paper, the X-ray diffuse scattering from a crystal of NaNO 2 at temperatures above the Neel temperature is analyzed to determine the nature of the inter-dipolar interaction in this substance.
Abstract: The X-ray diffuse scattering from a crystal of NaNO 2 at temperatures above the Neel temperature is analysed to determine the nature of the inter-dipolar interaction in this substance. By taking the Ising model, the space correlation is calculated with the random phase approximation leaving the coefficients of the short range interaction as parameters, and is compared with the observed intensity distribution of the diffuse scattering. It is found that a large part of the inter-dipolar interaction is of the electrostatic nature, and in addition to it, there are an antiferroelectric coupling between the neighbours along the a -axis and a ferroelectric coupling between the neighbours of the corner- and body-centre molecules. The coefficients of the short range interaction decrease with temperature more rapidly than that of the electrostatic interaction. The short range interaction may come from the covalent bonding between N and O and also from the Pauli repulsive interaction between the molecules.
TL;DR: In this article, the excitation cross-sections for the rotational and vibrational transitions are calculated on the basis of the Born approximation combined with the point-dipole interaction.
Abstract: The excitation cross-sections for the rotational and the vibrational transitions are calculated on the basis of the Born approximation combined with the point-dipole interaction. This calculation is partly the reconfirmation and partly a slight extension of the previous treatments. The validity of this treatment is examined. It is concluded that the treatment is not applicable for the incident energies around and above 1 eV because of an effect of large distortion in the wave function of the scattered electron. Possibilities of improving the theory are briefly discussed.
TL;DR: The magnetic structure of Fe 2 As has been determined by neutron diffraction as discussed by the authors, and the magnetic moments lie perpendicular to the c -axis of the magnetic unit cell with the c-axis twice as large as the chemical unit cell.
Abstract: The magnetic structure of Fe 2 As has been determined by neutron diffraction The compound Fe 2 As is antiferromagnetic with the Neel point at about 80°C Its magnetic structure is different from Mn 2 As The coupling between layers of iron atoms Fe(II) located at (0, 1/2, z ) and (1/2, 0, \bar z ) is antiparallel, but the coupling between a layer of iron atoms Fe(I) located at (0, 0, 0), (1/2, 1/2, 0) and adjacent Fe(II) layers is parallel The magnetic unit cell has the c -axis twice as large as that of the chemical unit cell The magnetic moments are 128 and 205 Bohr magnetons for Fe(I) and Fe(II) atoms respectively The moments lie perpendicular to the c -axis
TL;DR: In this paper, the so-called p-band patterns observable within a single T-domain of NiO under a polarizing microscope were confirmed to come from the magnetic domain structure due to the existence of S-walls, whose crystallographic aspects are just as predicted in the preceding paper.
Abstract: The so-called p-band patterns, i. e. , fine lamellar patterns observable within a single T-domain of NiO under a polarizing microscope, have been confirmed, with the use of X-ray techniques, to come from the magnetic domain structure due to the existence of S-walls, whose crystallographic aspects are just as predicted in the preceding paper. From observed behaviours of S-domains in applied magnetic fields, the easy directions of magnetization within the easy plane (111) are determined to be turnrightup.eps[11\bar2], but not turnrightup.eps[1\bar10]. By observing the domain structures with Berg-Barrett method, the magnitude of spontaneous magnetostriction is obtained as | e x ' x ' - e y ' y ' |=(9±3)×10 -5 and e z ' x ' /( e x ' x ' - e y ' y ' )=-0.18±0.06, where the x '-axis is taken along the spin axis, and the z '-axis along [111].
TL;DR: In this paper, the dispersion relation for weak, plane disturbances in a uniform plasma is derived, and the propagation of hydromagnetic waves in collisionless plasma is investigated on the basis of the Chew-Goldberger-Low approximation.
Abstract: The propagation of hydromagnetic waves in collisionless plasma is investigated on the basis of the Chew-Goldberger-Low approximation. The dispersion relation for weak, plane disturbances in a uniform plasma is derived. It is found that there exist the fast and slow modes of magnetoacoustic waves as well as the Alfven wave. However, under certain conditions the phase velocities of the slow and the Alfven waves become imaginary: namely the system is not necessarily totally hyperbolic but can be partially elliptic. The conditions on the elliptic cases are investigated in detail, especially for the slow wave. Then the propagation of a wave diverging from a point source is investigated graphically as well as analytically. The general theory of steady flow is also given, and some discussions are done for the two dimensional aligned field-flow in which the directions of magnetic field and flow are aligned everywhere.
TL;DR: In this article, the authors investigated the absorption, excitation and emission spectra and luminescent decay of CsI:Tl over the temperature range from 2°K to 300°K.
Abstract: Absorption, excitation and emission spectra and luminescent decay of CsI:Tl have been investigated over the temperature range from 2°K to 300°K. Six absorption bands are observed in contrast with four absorption bands A, B, C, and D in alkali halide-thallium phosphors having the NaCl structure. There exists no other absorption band having a character of the forbidden line as the B band. At 10°K, four emission bands are observed. The luminescent decay is composed of the fast and slow components and is somewhat complicated. For the purpose of comparison, the experiments on CsBr:Tl are also described.
TL;DR: In this paper, the resistivities and magnetic susceptibilities of lanthanum containing small amounts of other rare-earth metals have been measured at low temperatures and the observed resistivity of all the alloys contains a term proportional to log T in accordance with the recent theories on the s - d or s - f resistivity due to Kondo and others.
Abstract: The resistivities and the magnetic susceptibilities of lanthanum containing small amounts of other rare-earth metals have been measured at low temperatures. Resistance minima have been found at about 6.5°K in fcc La-Ce alloys and at about 5.8°K in hcp La-Ce alloys. The temperature at which the resistance minimum occurs is independent of the concentration of Ce. Any minimum has not been found in the alloys with solutes other than Ce. The observed resistivity of all the alloys contains a term proportional to log T in accordance with the recent theories on the s - d or s - f resistivity due to Kondo and others. The magnetic susceptibilities of La-Ce, La-Pr, and La-Nd alloys are not inconsistent with the resistive behaviors of these alloys. The effective s - f exchange integrals for various rare-earth solutes have been calculated from the resistivity data and compared with those calculated from the change of the superconducting transition temperature of La due to added rare-earth metals. The agreement between...
TL;DR: In this article, the Weizsacker correction is introduced into the TFD theory with a constant weighting factor λ( = 0.2) and this extended statistical equation is solved for the electron distribution of the inert gas atoms Ne, Ar, Kr and Xe.
Abstract: According to the result obtained in a previous paper (J. Phys. Soc. Japan 20 (1965) 1051), the Weizsacker correction is introduced into the TFD theory with a constant weighting factor λ(=0.2) and this extended statistical equation is solved for the electron distribution of the inert gas atoms Ne, Ar, Kr and Xe. The values of the total energy calculated on this basis agree very well to the Hartree-Fock values. The diamagnetic susceptibilities, however, still have a poor coincidence although the present model gives definitely better results compared to the simple TF or TFD theory. One electron energy values or the occupied states in Kr atom are also calculated by the Bohr-Sommerfeld quantization condition.