Journal of the Physical Society of Japan
Online ISSN : 1347-4073
Print ISSN : 0031-9015
ISSN-L : 0031-9015
Volume 56, Issue 10
Displaying 1-50 of 54 articles from this issue
  • Junji Suzuki, Takeo Izuyama
    1987 Volume 56 Issue 10 Pages 3401-3404
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    An elastic model for the membrane is studied using the renormalization group approach of the momentum shell recursion method. It is shown that this model exhibits a phase transition between the flat surface phase and the rough one.
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  • Fujihiro Hamba
    1987 Volume 56 Issue 10 Pages 3405-3408
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Constants in the k−ε model are estimated using the statistics obtained from a large eddy simulation of a turbulent mixing layer. Estimated values are compared with those usually adopted in the k−ε model and those derived by statistical analysis. It is shown that the estimate using large eddy simulation can give an important clue to the optimization of the constants and improvement of the model.
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  • Shunjiro Ikezawa, Keisuke Kida, Tomiya Yamazumi, Yoshinori Taki, Tatsu ...
    1987 Volume 56 Issue 10 Pages 3409-3412
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    Circularizers in an endless mirror device with l=2 and l=3 helical windings were designed using computer calculations of the magnetic surfaces. The parameters determined were substituted into the approximate equations obtained by E. Friman et al. to confirm their adequacy. It was found that the circularizer pitch is two and three times larger than that in a helical system of l=2 and l=3, respectively; that the circularizer may be mounted anywhere in the mirror part; and that the circularizer current Ic needs about one third that required of helical systems.
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  • Hironobu Maeda, Naruhiko Bamba, Akihisa Koizumi, Yuzo Yoshikawa, Tadao ...
    1987 Volume 56 Issue 10 Pages 3413-3416
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    The temperature dependence of the EXAFS (Extended X-ray Absorption Fine Structure) method has been carried out to study high-Tc superconductors of composition Y1−xBaxCuO3−δ with x=0.6. The anomalous behavior of the Debye-Waller factor in the superconducting transition region is observed, which may result from the breathing-mode vibration of oxygen atoms around Cu atoms, as reported in the oxide superconductor La–Sr–Cu–O system.
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  • Takumi Kikegawa, Hiroshi Iwasaki
    1987 Volume 56 Issue 10 Pages 3417-3420
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    In situ high-pressure X-ray and synchrotron radiation diffraction data for polycrystalline arsenic at ambient temperature show that it undergoes transition from the rhombohedral A7-type structure into the primitive simple cubic structure at a pressure of around 32 GPa and that this structure remains stable at least up to 45 GPa. The observation is in an agreement with the theoretical prediction by Mattheiss, Hamann and Weber (Phys. Rev. B34 (1986) 2190), but the trautsition occurs at a more reduced volume (VV0∼0.74) than that which was calculated.
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  • Toshio Soda
    1987 Volume 56 Issue 10 Pages 3421-3424
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    A new estimate of the transition temperature Tc of the superfluidity is made from the attractive interactions intermediated by the Bogoliubov phonon between two 3He particles in the background of the Bose condensed ground state of 4He, using the pseudopotential between helium particles and the magnitude of the correlation length of 4He. The precursors both in the proximity effect of superfluid 3He to the solution and the diffusion coefficient of the two-dimensional 3He–4He film are shown to have the divergence of the type of the inverse of TTc as the temperature T approaches Tc from the above, as in the Curie-Weiss law of the magnetic susceptibility.
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  • Hiroshi Iwasaki, Shigehiko Hasegawa, Makoto Akizuki, Sung-Te Li, Shogo ...
    1987 Volume 56 Issue 10 Pages 3425-3428
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    Diffuse spots slightly displaced from the (\sqrt3×\sqrt3) positions were observed in the high-temperature (1×1) state of Si (111) by low-energy electron diffraction. The spots showed threefold 3m symmetry and rotated around the \sqrt3 positions with changes in primary energy. These are reproduced by kinematic calculations for a surface configuration with adatoms distributed randomly over both the threefold-hollow and threefold atop sites of a (1×1) substrate with the exclusion of forming bonds with a common substrate atoms.
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  • Takehiko Mori, Kenichi Imaeda, Reizo Kato, Akiko Kobayashi, Hayao Koba ...
    1987 Volume 56 Issue 10 Pages 3429-3431
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    The electrical resistivity of an organic metal, (DMDCNQI)2Cu (DMDCNQI: 2,5-dimethyl-N,N′-dicyanoquinonediimine) is measured under pressure. Though this compound retains a metallic state down to 1.5 K at ambient pressure, a metal semiconductor transition appears above 4.5 kbar, and the transition temperature increases with an increase in pressure. On the analogy of the related compounds, this transition is attributed to a kind of one-dimensional instability.
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  • Shozo Takeno
    1987 Volume 56 Issue 10 Pages 3432-3435
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Superconductivity by electron pairing in real space is modelled by a reduced Hamiltonian in pseudo-spin form, which is similar to the Hamiltonian for a planar Heisenberg ferromagnet in an external field. By making correspondence of coherent states of the model pseudo-spin system to superconducting states, an effective, zero-temperature Ginzburg-Landau (GL) equation is derived. Pseudo-spin parameters are evaluated from the GL parameters obtained by Meissner effect measurement and other methods for Ba2YCu3O6.9 with Tc=91 K. The numerical value of Tc is estimated by using the mean-field approximation. The result so obtained is shown to be in fairly good agreement with the experimental result.
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  • Koichi Kikuchi, Keizo Murata, Yoshiaki Honda, Takahisa Namiki, Kazuya ...
    1987 Volume 56 Issue 10 Pages 3436-3439
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    We discovered superconductivity at ambient pressure in (DMET)2I3 at 0.47 K and in (DMET)2IBr2 at 0.59 K (midpoints), where DMET is (dimethyl(ethylenedithio)diselenadithiafulvalene), while in (DMET)2I2Br, superconductivity was not observed down to 0.5 K. In the DMET salts, those with smaller molar volume exhibit higher transition temperature, contrary to the BEDT–TTF salts. The effect of the disorder of the anion orientation on superconductivity is discussed.
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  • Katsurou Hanzawa, Kei Yosida
    1987 Volume 56 Issue 10 Pages 3440-3443
    Published: October 15, 1987
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    A possible mechanism for superconductivity in heavy-fermion systems is presented on the basis of the infinite-U periodic Anderson model. It is shown that the interaction between a strongly correlated electron (f-electron) and a weakly correlated electron (conduction electron) resulting from a virtual exchange of density fluctuation of the strongly correlated electrons is attractive for singlet pairing. The expressions of the free energy and the self-consistent equations for the gap parameter and TC are obtained in the Hartree-Fock approximation. Similar considerations can also be applied to high-TC superconductors in which 3d-electrons of Cu2+ and p-electrons of O2− play roles of strongly correlated and weakly correlated electrons, respectively.
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  • Chiaki Uyeda, Akio Yamagishi, Muneyuki Date
    1987 Volume 56 Issue 10 Pages 3444-3446
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    A large magneto-volume effect is found in liquid-phase oxygen. The volume expansion ΔVV0 is 2.2×10−4 under the field of 80 kOe, which is about ten times larger than that in ferromagnetic Fe, Co or Ni metals. The effect is understood by the exchange repulsion between O2 spins polarized by an external magnetic field. The contribution of the magneto-volume effect to field-induced transparency is discussed.
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  • Takao Yoshinaga, Tsunehiko Kakutani
    1987 Volume 56 Issue 10 Pages 3447-3463
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    By using a nonlinear coupled transmission line which consists of two LC ladder lines connected by intermediary capacitors, characteristic properties of fast and slow mode solitons and their collisions (both overtaking and head-on collisions) are examined experimentally. The observed results show a good agreement with those predicted by the second order Korteweg-de Vries (K-dV) theory except for the phase shifts due to the collisions. A similarity of this line to a two-layer fluid in the long gravity wave region is also discussed.
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  • Yasuhiro Akutsu, Tetsuo Deguchi, Miki Wadati
    1987 Volume 56 Issue 10 Pages 3464-3479
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Using a generalized Alexander-Conway relation derived from a three-state exactly solvable model in statistical mechanics, new invariant polynomials for knots and links are explicitly evaluated. It is shown that the invariant polynomials for closed 3-braids are obtained recursively. It is also shown that the invariant polynomials are more powerful than the Jones polynomials.
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  • Shigeo Homma, Shozo Takeno
    1987 Volume 56 Issue 10 Pages 3480-3490
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    A sine-lattice equation sin (un+1un)−sin (unun−1)−\ddotun=0 is shown both analytically and numerically to exhibit approximate, but well-defined, one- and multi-kink solutions of the form un=A tan−1n⁄βn) for an arbitrary constant A>0, where the quantities αn and βn are simply discrete versions of the corresponding ones in the conventional sine-Gordon equation. This is due to the kink dispersion relation 4 sinh2(k⁄2)−ω2=0 entirely equal to the case of the Toda lattice solitons.
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  • Akira Nakamura
    1987 Volume 56 Issue 10 Pages 3491-3498
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Exact solutions of the 3+1 dimensional Toda equation, Δ log VnVn+1+2VnVn−1=0, where Δ≡∂2⁄∂x2+∂2⁄∂y2+∂2⁄∂z2 have been obtained. The boundary condition is the “molecule” condition which is vanishing Vn at both ends of the finite chain, VN=VN=0 or VN=VN−1=0. In the large molecule and small angle limit, the present solution reduces to the 2+1 dimensional cylindrical Toda soliton.
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  • Kunisuke Nisizima, Kazuyosi Ikeda
    1987 Volume 56 Issue 10 Pages 3499-3511
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    The exact expressions for the volume-dependent cluster sums (composed of four or less molecules) for the three-dimensional simple cubic lattice gas (in a cube-shaped vessel) with nearest and second nearest neighbour interactions are obtained. The detailed behaviour of the cluster sums for the simple cubic lattice gas as functions of the volume of the vessel is investigated for the case when the nearest neighbour interaction is repulsive and the second nearest neighbour interaction is attractive. On the basis of their behaviour, the condensation phenomenon of such a lattice gas is discussed by applying Ikeda’s theory of condensation of systems satisfying the G-condition.
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  • Katsuhiko Nishimura, Susumu Ohya, Naoshi Mutsuro
    1987 Volume 56 Issue 10 Pages 3512-3514
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    Nuclear magnetic resonance on oriented 73Se in an iron host has been observed at about 7 mK. From resonance-shift measurement, the magnetic hyperfine-splitting frequency νM, g-factor and magnetic hyperfine field were derived as νM=102.61(3) MHz, |g(9⁄2+)|=0.188(16) and BHF(73SeFe)=716(81) kG. The experimental values of the g-factors of the g9⁄2 neutron states, in the neighborhood of the neutron number 40, are compared with the theoretical values based on the core-polarization model.
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  • N. Riahi
    1987 Volume 56 Issue 10 Pages 3515-3524
    Published: October 15, 1987
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    Weakly nonlinear thermal convection in a horizontal fluid layer bounded above by a free surface is studied by taking effects of the surface tension gradient into account. It is found that the critical Rayleigh number, the horizontal size of convection cells and the instability of the convection can be affected by the surface tension gradient. The heat transported by the convection may have a maximum value at a certain value of the Marangoni number M. For the particular range of M, the hexagonal flow pattern may arise with either upward or downward motion at the cells’ centers.
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  • Takayuki Aoki, Keishiro Niu
    1987 Volume 56 Issue 10 Pages 3525-3533
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    The linear stabilities of a rotating and propagating light ion beam in a low-density plasma are studied numerically on the basis of the hydromagnetic equations. The centrifugal force acts on the beam and the self-magnetic fields are induced by the rotating and propagating charged particles. To clarify the physical mechanism, a simple model characterizing a rotating and propagating beam is utilized, and it is found that the centrifugal force and the magnetic field in the azimuthal direction play a role of stabilization. Under such beam parameters which are practically required for the energy driver for inertial confinement fusion, the numerical results indicate that the beam in the equilibrium state is stable if the ratio of the beam-rotating velocity to the propagating one is more than the value of 0.8.
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  • Shunjiro Ikezawa, Yoshiaki Ishizaki, Tomiya Yamazumi
    1987 Volume 56 Issue 10 Pages 3534-3542
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    An ECR discharge plasma source obtained through the use of ferrite magnets was studied especially focusing on the threshold electric field at the breakdown and the energy distribution of charged particles in the plasma produced. The microwave frequency was a little smaller than the electron cyclotron frequency by about 0.5∼1%, which was explained clearly by the electron trapping condition. The energy distribution of electrons has the second harmonic and strongly depends on the localizing of the microwave field.
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  • Katsuhiko Hasebe, Hiroyuki Mashiyama, Naohiro Koshiji, Sigetosi Tanisa ...
    1987 Volume 56 Issue 10 Pages 3543-3552
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    The crystal structure of [N(CH3)4]2ZnCl4 was studied at three temperatures, 30, 60 and 90°C, in the paraelectric phase and at 5.5°C in the ferroelectric phase by using the X-ray reflection data collected by an automatic four-circle diffractometer. The split-atom method and the significance test showed that the constituent ions are in disorder in the normal phase. In the ferroelectric phase, positional and thermal parameters and occupation probability of ions were calculated by the least-squares method. The density modulation of ZnCl4 and that of one kind of N(CH3)4 ion were closely incorporated.
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  • Kazuyoshi Yamada, Ichiro Hirosawa, Yasuhisa Noda, Yasuo Endoh, Yoshich ...
    1987 Volume 56 Issue 10 Pages 3553-3557
    Published: October 15, 1987
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    Neutron scattering experiments using single crystals of LaCu6 and CeCu6 revealed the same type of the structural phase transition from orthorhombic to monoclinic structure in both compounds. The softening of [100] transverse acoustic phonons associated with the structural phase transition was observed in the high temperature phase. The temperature dependences of the distortion angle in the monoclinic phase and of the acoustic soft phonon can be unified for both compounds as a function of the reduced temperature TTm. The major contribution to this phase transition was concluded to be attributed not to 4f electrons of rare earth ions but to 3d electrons of Cu ions.
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  • Eiji Kato
    1987 Volume 56 Issue 10 Pages 3558-3565
    Published: October 15, 1987
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    The mechanism of the glass transition of solvent quinoline in a polystyrene (quinoline) gel is studied by measurements of get length and depolarized Rayleigh scattering. It is found that the effect of intermolecular force between quinoline molecules and the polystyrene network is important in the glass transition of the solvent. Due to the force, fluctuations in orientations of solvent molecules are frozen and the molecules are bound to the network. With nearing the glass transition temperature, the intensity of a broad Rayleigh component decreases due to decrease of the number of solvent molecules fluctuating in the network and that of a narrow Rayleigh component increases due to increase of inhomogeneity of the gel density.
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  • Makoto Matsumoto, Shinya Wakoh
    1987 Volume 56 Issue 10 Pages 3566-3569
    Published: October 15, 1987
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    The electron-positron many-body enhancement effect on the two-dimensional angular correlation distribution of positron annihilation radiation (2D ACAR) inchromium is phenomelogically investigated. The enhancement parameters are determined so as to obtain the best fit of the theoretical 2D ACAR to the experimental one. Two kinds of enhancement are considered. The first is a state-dependent one. In this scheme two enhancement factors are used for sp electrons and d-electrons. For a hybridized state the value of enhancement is decided by a weighted mean of those two factors according to their partial populations in the state. The other is a character dependent one. In this scheme two enhancement factors are also used, but they are used to scale the partial wave functions in the electron wave coupled to the positron. The result using the character-dependent enhancement is very good, while that using the state-dependent one is not so good.
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  • Hisatoshi Yokoyama, Hiroyuki Shiba
    1987 Volume 56 Issue 10 Pages 3570-3581
    Published: October 15, 1987
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    The ground state of the Hubbard model on one-dimensional and two-dimensional square lattices is studied with the effective Hamiltonian derived for the strong correlation regime and Gutzwiller-type wave function. The non-half-filled band as well as the half-filled band is discussed. The variational Monte-Carlo method enables us to evaluate the energy for the singlet liquid (resonating-valence-bond state) and for Néel state. The result shows that the stability of the singlet liquid depends on the dimensionality of the system.
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  • Hisatoshi Yokoyama, Hiroyuki Shiba
    1987 Volume 56 Issue 10 Pages 3582-3592
    Published: October 15, 1987
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    As a continuation of a previous paper [J. Phys. Soc. Jpn. 56 (1987) 1490], the variational Monte-Carlo method is extended to include the antiferromagnetic long-range order. The theory is based on the Gutzwiller-type correlation factor and its effect is exactly taken into account by the Monte-Carlo procedure. An application is made to the half-filled-band case of one-dimensional lattice (50 sites), two-dimensional square lattice (up to 20×20 sites) and three-dimensional simple cubic lattice (6×6×6 sites). The result is qualitatively different from previous studies relying on the random-phase-type “Gutzwiller approximation.” The variational energy for two and three dimensions is favorably compared with Hirsch’s quantum Monte-Carlo data.
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  • Haruyuki Takahashi, Shigeru Tamaki, Shoichi Sato
    1987 Volume 56 Issue 10 Pages 3593-3597
    Published: October 15, 1987
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    The electron density distribution in AgBr was investigated on the basis of X-ray intensity data collected by single crystal diffractometry. It was verified from difference Fourier map that the charge tends to accumulate in the intermediate region between the neighbouring unlike atoms. The origin of the extra charge on the difference Fourier map is investigated in terms of the radial distribution of the valence electrons.It is pointed out that the estimated value of the diamagnetic susceptibility of AgBr based on the present result agrees consistently with the observed one.
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  • Atsutaka Maeda, Kunimitsu Uchinokura, Shoji Tanaka
    1987 Volume 56 Issue 10 Pages 3598-3608
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    The low-frequency broadband noise of K0.3MoO3 associated with the sliding motion of charge-density waves (CDW) was measured in the frequency range between 1 mHz and 1 MHz. The power spectrum of voltage fluctuation consists of several peaks and the 1⁄fα background spectrum. As a result of an analysis, the former was found to be directly related to the energy distribution of the hopping among metastable states of the CDW’s, and the energy distribution was estimated from the experimental data. On the other hand, the latter is considered to come from the interaction among semi-macroscopic moving CDW domains, which are weakly coupled with each other.
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  • Masaki Togashi, Tatsuya Okada, Satoru Ohno
    1987 Volume 56 Issue 10 Pages 3609-3615
    Published: October 15, 1987
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    The enhancement of the susceptibilities χd of liquid In2Te3, InTe4 and Te caused by addition of Cr, Mn and Fe solutes decreases gradually with increasing temperature. This suggests that Cr, Mn and Fe ions are in a magnetic state in these liquid solvents. Similarly, the d states of V, Co and Ni solutes become magnetic in liquid InTe4 and In2Te3 alloys. The trend of χd versus transition metal solute exhibits a large peak at Mn. The low density of states of a solvent at the Fermi level is reflected on large values of χd in these liquid solvents, compared with the values of χd in liquid metals. It is found that χd(Fe)>χd(Cr) and χd(Co)>χd(V) in these liquid solvents. This relationship is attributed to a low density of conduction electrons of a solvent.
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  • Satoru Ohno, Tatsuya Okada, Masaki Togashi
    1987 Volume 56 Issue 10 Pages 3616-3621
    Published: October 15, 1987
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    The electrical conductivity of the liquid InTe4 alloy increases with addition of Fe, Co and Ni solutes, and decreases with addition of Ti, V, Cr and Mn solutes. For the liquid In2Te3 solvent, the trend of the increase in the conductivity in the series of transition metal solutes exhibits a large peak at Ni and a small peak at V. The increase in the conductivity for Fe, Co and Ni solutes is considerably larger than that for other transition metal solutes. The remarkable increase in the conductivity caused by addition of transition metal solutes is closely related to the increase in the total density of states at the Fermi level due to the sp-d admixture effect.
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  • Masahiro Inoue, Tadashi Takemori, Kazuo Ohtaka, Ryozo Yoshizaki, Tunet ...
    1987 Volume 56 Issue 10 Pages 3622-3634
    Published: October 15, 1987
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    An inter-layer Cooper pairing mechanism is considered for layers of two-dimensional electrons which are coupled by the exchange of three-dimensional phonons. We propose that the high transition temperature of Ba–Y–Cu–O compound may originate from this mechanism because of the combined effects of the strong attraction due to phonon exchange and the substantially reduced Coulomb repulsion between paired electrons. Impurity effects and relative stability between the inter- and intra-layer Cooper pairings are discussed and a phase diagram is calculated.
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  • Mitsuo Kataoka
    1987 Volume 56 Issue 10 Pages 3635-3647
    Published: October 15, 1987
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    In order to elucidate the different behaviours of the helical spin density waves (HSDW) due to the antisymmetric and symmetric exchange interactions, spin waves in the conical spin density wave (CSDW) states and the induced ferromagnetic states (IFMS) under external magnetic fields are calculated by use of phenomenological Hamiltonians with and without the antisymmetric exchange interaction. It is found that the spin wave spectra for the two types of HSDW are strongly different from each other, especially in the magnetic field dependences, enough to be able to distinguish them. The ESR frequencies are also investigated theoretically for both types. In the light of these results, the observed magnetic field dependencies of the ESR frequencies in MnSi and Fe1−xCoxSi are discussed to prove the HSDW due to the antisymmetric exchange interaction in these compounds.
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  • Tosizumi Aoki
    1987 Volume 56 Issue 10 Pages 3648-3651
    Published: October 15, 1987
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    Without assuming the classical ground state with a symmetry breaking, we derived spin wave excitation in the antiferromagnetic quantum spin systems on the triangular lattice. The motion of z-component spin is investigated to second order in the time derivative within the effective-field approximation. The spectrum of excitation is calculated by the use of Miyashita’s trial function. The obtained spin wave excitation has a phonon-like spectrum, which is similar to the spin-wave one based upon the classical ground state, although its velocity is modified.
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  • Kazuyoshi Yoshimura, Kazuaki Fukamichi, Hiroshi Yasuoka, Mamoru Mekata
    1987 Volume 56 Issue 10 Pages 3652-3660
    Published: October 15, 1987
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    The Knight shift and the nuclear spin-lattice relaxation rate, 1⁄T1, of 59Co in LuCo2 have been measured. 1⁄T1T due to the d-electron spins was found to be proportional to the d-spin susceptibility in good agreement with the SCR theory. From the quantitative analysis, the characteristic temperature, T0, implying the energy width of the dynaical spin-fluctuation spectrum is estimated for LuCo2 together with those for the typical nearly ferromagnetic metals. The value T0 may be related to the degree of the ferromagnetic tendency as welll as the temperature of χ maximum in the nearly itinerant ferromagnet.
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  • Masatsune Kato, Kazuhiko Satoh, Yoshiteru Maeno, Yuji Aoki, Toshizo Fu ...
    1987 Volume 56 Issue 10 Pages 3661-3666
    Published: October 15, 1987
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    Specific heat of a dense-Kondo system, CexLa1−xCu6, has been systematically measured between 2 and 80 K in order to clarify the transition from dilute-Kondo to dense-Kondo behavior as the cerium concentration, x, increases. We have found that the magnetic specific heat per molar cerium, Cm, is nearly independent of x and is explained by a simple sum of the Kondo specific heat and the Schottky specific heat, with the x-independent energy separation between the ground and the first excited states (65 K). However, due to the interaction between the cerium ions, the first excited state tends to be broadened as x increases, and the width of the first excited state for the dense limit of CeCu6 (TK=3.9 K) is estimated to be about 20 K. At low temperatures, Cm increases as x is decreased. This tendency is qualitatively interpreted as due to the decrease in TK caused by the increase of unit cell volume.
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  • Atsunobu Nakamura, Norio Kawakami, Ayao Okiji
    1987 Volume 56 Issue 10 Pages 3667-3676
    Published: October 15, 1987
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    The low-frequency dynamical susceptibility for the Ce-Kondo system is investigated on the basis of the local Fermi liquid theory at zero temperature. The effects of the crystalline field are studied precisely by means of the Bethe-Ansatz solution of the Anderson model, for the cases of cubic, hexagonal and tetragonal fields. It is shown that the magnetic relaxation rate of the f-electron is enhanced in general in the presence of the crystalline fields. The anisotropic properties of the relaxation are discussed for hexagonal and tetragonal fields as well.
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  • Hideo Takeuchi, Masanori Arakawa, Hiroshi Ebisu
    1987 Volume 56 Issue 10 Pages 3677-3682
    Published: October 15, 1987
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    EPR measurements on Fe3+ centres in RbCdF3 and CsCdF3 for crystals co-doped with Li+ ions have been made in the cubic phase of host crystals. In both the crystals spectra from two kinds of Fe3+ tetragonal centres associated with Cd2+ vacancy (VCd) and Li+ ion at the nearest-divalent-cation sites have been observed. From obtained fine structure parameters in the spin Hamiltonian the metal-ligand distances have been determined by the superposition model. The fine structure parameters have been explained well by the obtained metal-ligand distances, which show the contraction or distortion of fluorine octahedra surrounding Fe3+ ions.
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  • Toshio Inase, Yoshiko Miyamoto
    1987 Volume 56 Issue 10 Pages 3683-3688
    Published: October 15, 1987
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    An electric polarization which contains spontaneous electric polarization and magnetoelectric polarization of magnetite was measured over a temperature range from 4.2 K to 60 K. The observed electric polarization is divided into two parts: one is due to rotation of magnetization and the other is independent of it. An anomalous behavior in temperature dependence was observed in both of these two parts at the same temperature of 6 K. In earlier reports, anomalous behaviors in pyroelectric polarization and in magnetoelectric polarization were measured individually at this temperature. Another anomaly was observed at about 45 K, which was interpreted as an effect due to the switching of the a axis to the b axis by the magnetic field. A change caused by breaking of the mirror symmetry was not observed at about 10 K in the present measurements.
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  • Tsuneaki Miyahara, Atsushi Fujimori, Tsuneharu Koide, Shigeru Sato, Sh ...
    1987 Volume 56 Issue 10 Pages 3689-3694
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    Near-noraml reflectance spectra of CeO2 and CexLa1−xAl2 alloy system were measured at photon energies from 90 to 140 eV. The results were compared with the photoyield data on CexLa1−xCu6 alloy system paying attention to the chemical shifts of the 4d-4f multiplet components. It was found that the rigid wavefunction model is not consistent with the concentration dependence of the chemical shifts.
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  • Youichi Ohno
    1987 Volume 56 Issue 10 Pages 3695-3702
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    Metal M2,3 inner-shell electron-energy-loss spectra in layered transition-metal tri-thiophosphates MPS3 (M=Mn, Fe, Ni) have been measured at low incident energies in reflection geometry. The spectra reveal the multiplet structures of the final states of localized divalent metal ions. The relative intensities of the peaks are varied systematically as incident energy decreases. Large deviation from the X-ray absorption spectra are found at low incident energies. The variations are interpreted in terms of the incident energy dependence of momentum transfer involved in the inelastic scattering process and exchange interaction between incident and target electrons. It is found that dipole selection rules are broken in 3p-3d transitions within the localized 3d transition-metal ions as incident energy approaches the excitation threshold.
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  • Keiichi Kaneto, Fumito Uesugi, Katsumi Yoshino
    1987 Volume 56 Issue 10 Pages 3703-3709
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Absorption and luminescence induced by a photoexeitation are studied in polythiophene and poly(3-methylthiophene) films. The photoinduced absorption spectra which are nearly consistent with those of dopant-induced absorption at dilute doping levels indicate that the dominant photoinduced charged species are polarons. It is found that the magnitude of photoinduced absorption is rather independent on the condition of sample preparation, whereas the photoluminecence intensity is strongly influenced. The result suggests that the luminescent exciton does not play a primary role in the photogeneration of polaronic species.
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  • Takenari Goto, Jun Maeda
    1987 Volume 56 Issue 10 Pages 3710-3714
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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    We have measured the absorption and luminescence spectra of the ultra-thin PbI2 film evaporated on a cleaved KCl crystal at 100 K. The energy of the exciton absorption band is analyzed by the one-dimensional quantum well, but the exciton energies in the platelet crystals consisting of the two and three layers deviate from the simple theoretical values because of the too thin crystals. From the appearance of the broad luminescence band in the ultra-thin film, it is concluded that the free exciton level may become higher than that of the self-trapped exciton by the quantum well effect.
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  • Hitoshi Nishimura, Yoshimitsu Saka, Shunji Nagata, Satoshi Hashimoto, ...
    1987 Volume 56 Issue 10 Pages 3715-3725
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Absorption, luminescence and excitation spectra of LiI crystals have been observed in a wide temperature range. Being extremely hygroscopic, LiI crystals were cleaved in liquid helium inside a cryostat before optical measurements. With this method of crystal cleavage, the luminescence spectrum of LiI is drastically changed. Experimental results have led to following conclusions: (1) the steepness constant of the exciton absorption (Urbach) tail is 0.87, (2) at least one self-trapped exciton state stably exists, (3) from the state one luminescence band peaking at 3.4 eV occurs and (4) the potential barrier between the free and the self-trapped exciton states is 55 meV. A possibility of the self-trapped exciton state in LiI to be of three-center type is discussed.
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  • Shin’ichi Katayama, Ryoichi Fukasawa
    1987 Volume 56 Issue 10 Pages 3726-3733
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    We present a theoretical description of the Raman spectra from longitudinal optical (LO) phonon modes confined in a heterostructure consisting of a thin surface layer on a semi-infinite substrate. The scattering cross section is derived by a dispersive continuum model for ionic displacement on the basis of classical response function theory. The spectra calculated for GaAs/AlGaAs reveal that phonon confinement in GaAs layer leads to asymmetric feature in line shape as well as peak shifts of the GaAs-type modes. The observability of the confined LO modes via Raman studies is discussed.
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  • Toshiaki Fujita, Koichi Kurita, Ken Takiyama, Toshiatsu Oda
    1987 Volume 56 Issue 10 Pages 3734-3739
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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    Absorption spectra near the fundamental absorption edge are studied in Sb2S3. Step-like structures characteristics to the indirect allowed exciton transition are found. The energy of the indirect exciton is determined to be 1.749 eV at 27 K. The band structure is calculated by the pseudopotential method and compared with the experimental results. It is shown that the top of the valence band and the bottom of the conduction band lie around Γ and X points, respectively, and that the smallest direct gap is located at around the X point.
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  • Fukuko Yuasa, Éi Iti Takizawa
    1987 Volume 56 Issue 10 Pages 3740-3741
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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  • Takayuki Shirakura, Osamu Ono, Sakari Inawashiro
    1987 Volume 56 Issue 10 Pages 3742-3743
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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  • Kenji Takanaka
    1987 Volume 56 Issue 10 Pages 3744-3745
    Published: October 15, 1987
    Released on J-STAGE: June 01, 2007
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  • Junji Iida, Yasuaki Nakagawa, Shunji Takekawa, Noboru Kimizuka
    1987 Volume 56 Issue 10 Pages 3746-3747
    Published: October 15, 1987
    Released on J-STAGE: May 29, 2007
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