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Hidetoshi Konno
1985 年 54 巻 12 号 p.
4475-4478
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The Burgers equation with an external noise is studied. We obtain the exact soltutions of the shock wave, the pulse wave and the initial-value problem for the spatially uniform noise. The behaviours of the average velocity under the Gaussian white noise is examined. It is shown how the external noise plays the role to diffuse steep slopes of waves.
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Hikaru Kawamura, Masaharu Tanemura
1985 年 54 巻 12 号 p.
4479-4482
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A Monte Carlo study is made on the two-dimensional plane-rotator (
XY) model on the square lattice with random ±
J interactions particularly with interest in the chirality degrees of freedom introduced by Villain. It is suggested that the model exhibits a phase transition at a finite temperature into a “chiral spin glass” phase.
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Masuo Suzuki
1985 年 54 巻 12 号 p.
4483-4485
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A general representation of the thermal quantum state is given for any interacting quantum system such as fermi, bose and quantum spin systems. A fundamental equation of quantum non-equilibrium systems is obtained on the basis of the time-dependent thermal quantum state |
Ψ(
t)〉.
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Yasuhisa Noda, Kazuyoshi Yamada, Ichiro Hirosawa, Yasuo Endoh, Yoshich ...
1985 年 54 巻 12 号 p.
4486-4489
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The structural phase transition of CeCu
6 has been studied by neutron scattering. The temperature dependence of the splitting angle of the Bragg point (0 2 0) corresponding to the distortion angle from the orthorhombic structure reveals that this transition is nearly of second order. The soft phonons associated with the structural phase transition were observed in the orthorhombic phase. The observed neutron groups with this phonon mode are extremely narrow even near the transition temperature.
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W. K. Chow, K. W. Wong, P. C. W. Fung
1985 年 54 巻 12 号 p.
4490-4493
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
We propose here that the amount of Bose-Einstein Condensation in a system of interacting boson should be a small value which tends to zero. Our calculation is based on the asymptotic behaviour of the radial distribution function which is derived from combining the methods of Correlated-Basis-Function and Canonical transformation.
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Takehiko Oguchi, Hidetoshi Nishimori, Yoshihiro Taguchi
1985 年 54 巻 12 号 p.
4494-4497
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The classical ground states of face centered cubic lattice with nearest neighbor antiferromagnetic Heisenberg interactions are shown to have continuous degeneracy. The spin wave theory removes the degeneracy and determines the ground state, in which the energy
Eg and spin reduction are calculated.
Eg is also obtained by calculating the lowest energy of finite size systems and extrapolating to infinite lattice. Both results are in fairly good agreement with each other. Finally it is concluded that the sublattice long range order exists.
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Nobumori Kinoshita, Madoka Tokumoto, Hiroyuki Anzai, Gunzi Saito
1985 年 54 巻 12 号 p.
4498-4501
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
Angular dependences of ESR
g factors and linewidths for α- and β-(BEDT–TTF)
2I
3 are measured at room temperature using and X-band ESR spectrometer. The principal values of the
g tensor are calculated using the anisotropic behavior of the measured
g value with the assumption that the principal axes of the
g tensor are orthogonal to each other. The estimated values of
gxx,
gyy and
gzz are 2.013, 2.005 and 2.001 for α-(BEDT–TTF)
2I
3 while 2.011, 2.008 and 2.002 for β-(BEDT–TTF)
2I
3, respectively. The anisotropic behaviors of the linewidth for α- and β-(BEDT–TTF)
2I
3 are mostly explained by the spin-phonon relaxation mechanism, the Elliot mechanism, except when the value of the
g shift is nearly zero.
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Yoshihiro Sato, Etsuo Shimada, Itaru Ohta, Shigeki Tasaka, Shinichiro ...
1985 年 54 巻 12 号 p.
4502-4505
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Energy spectrum of cosmic-ray Fe-nucleus has been measured from 4 GeV/n to beyond 100 GeV/n. The data were obtained using emulsion chambers exposed by a balloon launched from Sanriku, Japan. The energy of Fe nuclei was estimated by the opening angle method, the calibration of which was made using accelerator beams of 1.88 GeV/n Fe. The spectral index of Fe we obtained is −2.45±0.04 in the range from 10 to 200 GeV/n, confirming the previous results obtained by different methods and proving the powerfulness of the opening angle method for cosmic rays.
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Hitoshi Harada
1985 年 54 巻 12 号 p.
4507-4512
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
It is shown that the Burgers-Hopf(BH) hierarchy consisting of all the n-th BH equations is a subhierarchy of the KP hierarchy in the Sato theory. If is also shown that the totality of solutions of the BH hierarchy forms art infinite dimensional projective space. Since each of the equations of the BH hierarchy possesses the generalized Painlevé property defined by S. Oishi and the author, this result supports their conjecture that the generalized Painlevé property has a connection with the Sato theory.
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Naoyuki Tokuda
1985 年 54 巻 12 号 p.
4513-4523
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A convection Stefan problem with Newton’s radiation condition has been solved by a power series method based on the method of Lagrange-Bürmann expansion. After formulating the moving boundary problem as a fixed boundary problem by variable transformation, a series solution is developed in powers of a new ‘time-like’ variable. The nonlinear interfacial and boundary conditions reduce to Lagrange-Bürmann expansions for new dependent variables from which the interface position and the wall temperature functions are recovered by inverting the transformation. Compared with the classical series solution, the convergence of the new expansions is markedly improved, in fact extending over the entire physical time domain of
t∈[0, ∞) for sufficiently small Stefan number.
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Noriko Saitoh, Éi Iti Takizawa, Shôzô Takeno
1985 年 54 巻 12 号 p.
4524-4529
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A systematic scheme to analyse the two-(space)-dimensional Toda lattice (2DTL) equation is proposed, making use of recurrence formulae similar to those of cylindrical functions. This scheme maintains a method to make linearize 2DTL equation and enables us to find various solutions, as well as ripplon-type solutions, by means of adjusting a set of coefficients of recurrence formulae.
Several solutions are obtained by this method. A Bäcklund transformations is also found in this scheme to analyse the 2DTL equation. The compatibility condition to make linearize 2DTL equation is reduced to the original 2DTL equation itself.
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Hikaru Kawamura, Seiji Miyashita
1985 年 54 巻 12 号 p.
4530-4538
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Phase transitions of the two-dimensional classical Heisenberg antiferromagnet on the triangular lattice are studied in the presence of magnetic fields. Three types of ordered phase and successive phase transitions among them are found. Properties of each phase are investigated by means of a Monte Carlo similation.
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Ch. Suryanarayama, N. Venkateswara Rao, S. Bhuloka Reddy, G. Satyanara ...
1985 年 54 巻 12 号 p.
4539-4543
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The total conversion coefficient of the 150.6 keV (E3) transition in the decay of 11⁄2
− state (
T1⁄2=48.6 minutes) in
111mCd is determined employing a high resolution HpGe detector system and the intensity balance method. The experimentally measured α
T is found to be 1.76±0.08 and deviate from the theoretical value of Hager and Seltzer by (23±3)%. The E3 hindrance with respect to the single particle estimate is determined to be 8.5×10
3. The results are discussed.
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Kunizo Onda
1985 年 54 巻 12 号 p.
4544-4554
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Collision cross sections for rotational excitation processes of a molecular nitrogen by electron impact are calculated at the energy range of 0.01 to 3 eV. It is shown that integrated cross sections for rotationally inelastic scattering are noticeably enhanced by the short range interaction between the scattered electron and the target nitrogen molecule at the impact energy as low as 0.08 eV.
At the energy region of the well-known
Πg resonance, it is confirmed that the cross section for the rotational excitation of
j=0 to
j′=4 becomes larger than that for
j=0 to
j′=2 by more than the ratio of statistical weight (2
j′+1) of the final rotational state
j′. An explanation to this fact is given by analysing the expression of the integrated cross section.
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Kohji Fukuda, Akira Inouye, Yutaka Kawabe, Akira Hirai
1985 年 54 巻 12 号 p.
4555-4560
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The transition from the laminar flow to the turbulent flow of water in a long circular pipe has been studied by observing the spin echo amplitudes in a pulsed NMR method. The spin echo signal is characteristic to the flow condition, i.e., its amplitude is large when the flow is laminar, while it is small when the flow is turbulent. In the transition region spin echo signals with large amplitudes and those with small amplitudes appear intermittently. The intermittency factor of the flow has been measured in the transition region. This experiment shows That the pulsed NMR method might be useful to study dynamical characters of the transition region.
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Toshiyuki Nishitani, Kazushi Ishii
1985 年 54 巻 12 号 p.
4561-4569
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Similarity transformations of the Navier-Stokes equation for the incompressible fluid are studied by means of invariant transformation. It is shown that assumptions of transformation from three to two independent space variables produce three different types. One of the transformations is found to be equivalent to that of Lundgren and the others are new. Further, reduction of variables for the two dimensional equation to one space variable is discussed. A generalized form of Kambe’s transformation is obtained.
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Shobu Kaneko, Hiroaki Tsutsui, Takeshi Miyazaki, Masayoshi Taguchi
1985 年 54 巻 12 号 p.
4570-4575
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The magnetohydrodynamic equilibrium states by Hill’s vortex model and by the Coulomb-wave-function model are proved to be unstable. New MHD equilibrium configurations are determined by using another model for which d
p⁄dψ=0 on the magnetic axis. Here
p is the pressure and ψ is the flux function. The values of the safety factor on the magnetic axis,
qaxis, are evaluated for these configurations. The MHD stability of these equilibrium states is investigated by the Mercier criterion. The values of the maximum beta ratio β
max are evaluated for this model. The optimized pressure distributions are determined by use of the Mercier criterion and the values of β
max are also evaluated for these pressure distributions. The values of β
max are shown to be at most 12%, if the condition
qaxis<1 is required.
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Hikaru Terauchi, Satoshi Sekimoto, Kousei Kamigaki, Hirofumi Sakashita ...
1985 年 54 巻 12 号 p.
4576-4585
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
X-ray diffraction measurements of semiconductor superlattices grown by molecular beam epitaxy (MBE) have been carried out. Alternating monolayer growth of GaAs and AlAs has been confirmed by detecting the reflections at Brillouin zone boundaries in the reciprocal space. In strained GaAs–Ga
1−xIn
xAs superlattices the tetragonal distortion is found and the tetragonality is independent of the thickness of the strained layer but increases with decreasing thickness of the GaAs layer. The X-ray study of the interdiffusion in the superlattice has been also carried out.
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Nitish K. Sanyal, S. N. Tiwari, M. Roychoudhury
1985 年 54 巻 12 号 p.
4586-4591
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
A theoretical analysis of the nematic behaviour of
p-
n-propoxybenzoic acid has been carried out on the basis of inter-molecular interaction energy calculations. CNDO/2 method has been employed to compute net atomic charges and atomic dipole components at each atomic centre of the molecule. Using the quantum-mechanical charge distribution, intermolecular interaction energy between a pair of
p-
n-propoxybenzoic acid molecules has been evaluated using second order perturbation theory and multicentered-multipole approximation method. Stacking as well as in-plane lateral interactions between a pair of the molecules, have been taken into account. On the basis of results obtained, an attempt has been made to elucidate the molecular ordering and other related parameters responsible for the mesomorphism of the system.
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Yoshiaki Kogure, Toshio Kosugi, Yosio Hiki
1985 年 54 巻 12 号 p.
4592-4599
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The pressure dependence of the damping constant for a moving dislocation has been calculated and evaluated with the intension of being compared with our results of high pressure experiments. The calculations were made on the basis of the mechanisms of phonon scattering (Leibfried, Klemens, and Brailsford), thermoelastic effect (Eshelby), phonon viscosity (Mason), and fluttering effect (Ninomiya). Pressure derivatives of various quantities appearing in the formulations of these mechanisms were firstly calculated, and then the pressure dependence of the damping constant was evaluated. The higher order elasticity theory could conveniently be used in these calculations. The numerical evaluations were made for the cases of LiF, NaCl, and Al crystals. The experimental second- and third-order elastic constants and the theoretical fourth-order elastic constants were adopted in these evaluations.
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Seishi Yamamoto, Yasuhiro Shinnaka
1985 年 54 巻 12 号 p.
4600-4606
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
An intensity formula for X-ray diffuse scattering due to an orientation-phonon coupling in multi-orientation system is obtained by extending Naya’s theory in the random phase approximation (RPA). By the use of this formula, diffuse maximum observed in cubic NaClO
4 is analysed and the mechanism of cubic-orthorhombic transition in NaClO
4 is clarified.
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Akira Yoshihara, Takashi Suzuki, Tadao Fujimura
1985 年 54 巻 12 号 p.
4607-4620
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A Landau theory of the D
4h17–D
2h18–D
2h15 successive phase transitions has been developed and applied to the successive phase transitions in the layered perovskite compound (C
2H
5NH
3)FeCl
4. Characteristic features of the Brillouin scattering and the ultrasonic results in the phases I, II, III could be well explained. The dielectric anomaly at the II–III phase transition could be also explained.
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Takao Yamauchi, Kazunori Takayanagi, Hiroyuki Yamaguchi
1985 年 54 巻 12 号 p.
4621-4625
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
In order to examine a role of vacancies in ordering during quenching, the residual electrical resistivity of β-brass has been studied as a function of quenching temperatures ranging from 100 to 450°C. The resistivity immediately after quenching first increases exponentially with increasing temperatures up to 275°C and then decreases gradually although it increases again over 400°C. The first increase is ascribed to wrong atoms on copper and zinc sublattices and the resistivity per their one atomic percent is estimated to be 1.8×10
−8 Ωcm.
The recovery of quenched specimens occurs even annealing at around room temperature with associated activation energy of about 0.6 eV, which is assigned to the recovery of wrong atoms.
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Takao Yamauchi
1985 年 54 巻 12 号 p.
4626-4630
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Changes in concentration of wrong atom of Cu or Zn on its sublattice, single vacancy and divacancy associated with ordering in β-brass during quenching have been studied by means of a computer simulation taking account of the cooling rate. The concentration of wrong atoms just after quenching increases with increasing temperatures up to 275°C and then decreases gradually while that of single vacancy or divacancy increases exponentially with the increase of temperatures. By using the result, the observed change in resistivity depending on the quenching temperature can be well interpreted quantitatively.
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Eiiti Tamura
1985 年 54 巻 12 号 p.
4631-4635
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The theory of secondary electron emission (SEE), which was proposed by Feder and Pendry, is extended. The new argument allows us to predict not only the fine structure but also all the features of SEE spectra. The secondary electron current is described as a multiplication of the fine structure part, which is easily obtained by dynamical low-energy electron diffraction (LEED) theory and the cascade function for the electron-gas system. Good agreement is found in the comparison between the theory and experiment for Cu(100) and (111) surfaces.
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Junjiro Kanamori, Masakuni Okamoto
1985 年 54 巻 12 号 p.
4636-4647
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The interrelation among the (2×8), (2×7) and (5×5) reconstruction states of the (111) surface of pure Ge, Si and related systems is discussed on the basis of the previously proposed lattice gas model. It is pointed out that the model corresponds to the two dimensional ANNNI model if interaction parameters stabilize these states as the ground state. It is shown that the (7×7) and (5×5) states correspond to networks of the walls separating the regions of different spin directions and the (2×8) one to a parallel configuration of the walls. It is conjectured on the basis of this correspondence that the floating phase discussed by Villain and Bak may exist in a temperature range inbetween the (2×8) phase and the disordered one in the case of Ge(111). Relevant experimental data are discussed.
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Satoshi Itoh, Kenji Nakao
1985 年 54 巻 12 号 p.
4648-4656
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A new procedure is presented for the self-consistent calculation of the electronic structure of a large-sized cluster with a low-symmetry. This is based on the numerical-basis-set LCAO method and the norm-conserving pseudopotential, and contains no adjustable parameters. Owing to such contrivances, we can calculate the electronic structure of the large-sized cluster with a small number of basis functions per atom. The electronic structure of monoclinic selenium is calculated by using this method, and we obtain a good agreement between calculated and observed properties such as cohesive energy and equilibrium bond length, without a huge computational time.
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Satoshi Itoh, Kenji Nakao
1985 年 54 巻 12 号 p.
4657-4667
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The electronic structure of the structural defects in sulfur is investigated on the self-consistent numerical-basis-set LCAO method. The ground states of the isolated one-fold and three-fold coordinated defects are shown to be always neutral, and it is also shown that the isolated one-fold coordinated defect is more stable than the three-fold coordinated one, in contrast to the customary qualitative model for these defects. Furthermore, the characteristic defect states are found to appear in the band gap. Based on these results, the electronic state of the complex defect is also discussed briefly.
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Naoshi Suzuki, Atsushi Yamamoto, Kazuko Motizuki
1985 年 54 巻 12 号 p.
4668-4679
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Physical properties of the CDW state of 1
T-TiSe
2 such as electronic band structures are investigated on the basis of the band-type Jahn-Teller model by extending our microscopic theory of lattice instability in the normal phase. The results are summarized as follows: (i) The triple-
q CDW state is more stable than the single-
q CDW state as observed. (ii) The magnitude of the lattice distortion for the triple-
q structure at
T=0 K is close to the observed value. (iii) The largest CDW gap is obtained to be about 0.2 eV, which agrees in order of magnitude with the optically determined gap 0.4 eV. (iv) On formation of the CDW the density-of-states at
EF decreases considerably and a peak develps at 0.1 eV below
EF, which is consistent with the observation by photoemission.
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Yasushi Ohfuti, Yoshiyuki Ono
1985 年 54 巻 12 号 p.
4680-4687
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Variations of fractionally charged kinks with coupling constant is investigated in the 1/3-filled Su-Schrieffer-Heeger model. Numerical analyses are carried out for chains consisting of about 480 lattice points. Creation energies and widths of kinks are calculated for various coupling constants. The weakest one yields a kink with a width of the order of 100 lattice constants. The electronic energy level structures have one or two localized gap states for kinks with charges ±2
e⁄3 or ±
e⁄3, respectively. They remain to exist even in the case of the weakest coupling constant investigated.
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Shoji Ishida, Setsuro Asano
1985 年 54 巻 12 号 p.
4688-4694
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The electronic structures of paramagnetic and ferromagnetic ScFe
2 are calculated self-consistently using the KKR method in the framework of the local-spin-density approximation for the exchange-correlation potential. The general electronic structures are similar for both of the atom Fe(2
a) at the 2
a sites and the atom Fe(6
h) at the 6
h sites. However the difference is seen near the Fermi level in the densities-of-state of
d bands between Fe(2
a) and Fe(6
h). This difference induces a small difference in the magnetic moments between the two Fe; the values are 1.40 μ
B/Fe(2
a) and 1.46 μ
B/Fe(6
h). The atom Sc also carries a magnetic moment of 0.27 μ
B/Sc with the direction opposit to the moment of Fe.
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Shoji Ishida, Setsuro Asano, Junji Ishida
1985 年 54 巻 12 号 p.
4695-4703
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The band structures of AFe
2(A=Mo, Hf, Ta, W) were calculated to examine the influence of the atom A on the electronic structures and the magnetic properties. The band structures are essentially unaffected by the difference in the kind of
d bands of the atom A. The hybridization between
d states of A and Fe becomes stronger with increasing the number of valence electrons of the atom A and affects the DOS curves of Fe(2
a) and Fe(6
h) around the Fermi level which are closely related with the magnetic properties for the C14 compounds. However, since the variation of the electronic structure with the change of the atom A is not so drastic, we can roughly guess the magnetic properties of the C14 compounds with the rigid-band-model.
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Yoshiyuki Ono, Hidetoshi Fukuyama
1985 年 54 巻 12 号 p.
4704-4711
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
In the quantum limit of strong magnetic fields, the electronic polarization function of non-interacting systems is calculated within the ladder approximation for impurity scatterings. The diffusion constants are shown to have strong anisotropy depending on the purity of the sample; i.e. the diffusion constant in the parallel direction to the field is much larger than that in the parpendicular direction. The anisotropy gets stronger as the sample gets purer. Since the polarization function is closely related to the phonon damping, this anisotropy of the diffusion constants leads to that of the ultrasonic attenuation coefficients, which is explicitly calculated for several values of material parameters which may be realized in typical semimetals such as Bi.
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Shinji Kawaji, Kenji Maeda
1985 年 54 巻 12 号 p.
4712-4716
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A positive magnetoresistance which is independent of the field direction has been observed in Si(100)
n-channel inversion layers. Magnetic field and temperature dependences of the magnetoconductivity in the field parallel to the interface have been measured in the field up to 1.7 T at temperatures between 4.2 K and 1.1 K. The magnetoconductivity
Δσ
⁄⁄(
B)⁄σ(0) is described as a function of
B⁄(
T−θ), where the characteristic temperature θ depends on the conductivity and θ<0. No existing theory can explain the experimental results.
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Shinya Hosokawa, Makoto Yao, Toshiyuki Yoshimura, Hirohisa Endo
1985 年 54 巻 12 号 p.
4717-4725
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The electronic properties of liquid Se containing Na, K, Cl, Br and I have been measured. The addition of alkali impurities causes a substantial increase in the electrical conductivity σ and changes the thermoelectric power
S from positive to large negative. When halogen impurities are added to liquid Se, σ increases remarkably and
S remains positive. No appreciable change in paramagnetic susceptibity is induced by alkali or halogen doping. The alkali doping produces a new optical absorption band near the absorption edge of pure liquid Se, while no appreciable change in the absorption curves can be detected for the halogen doping. It is pointed out that the Fermi level is shifted owing to the charge transfer from the dopant element to Se chains.
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Takashi Nakayama, Hiroshi Kamimura
1985 年 54 巻 12 号 p.
4726-4734
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
The band structures of ultrathin layered superlattices (GaAs)
n/(AlAs)
n with
n=1, 2, 3 and 4 are calculated by the self-consistent pseudopotential method. In this calculation a value of α in the Xα approximation for the exchange-correlation potential is adjusted so as to reproduce both band gaps of GaAs and AlAs. This reflects an effect of the self-energy correction. The resulting band structures and charge densities show that upper valence band states of (GaAs)
n/(AlAs)
n with
n=1 to 4 are approximately obtained by folding the valence bands of GaAs and AlAs, while that lower conduction band states correspond to strong hybridization of folded bands of GaAs and AlAs. It is shown that the band gap of (GaAs)
1/(AlAs)
1 is indirect, while those for
n=2 to 4 are direct and decrease with increasing n. This trend is consistent with recent experimental results.
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Hiromichi Ebisawa, Hidetoshi Fukuyama, Sadamichi Maekawa
1985 年 54 巻 12 号 p.
4735-4742
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Effects of strong spin fluctuations in itinerant systems on the critical temperature,
Tc, of superconductivity have been investigated in the weakly localized regime both for two and three dimensions. It turns out that
Tc is reduced in proportion to the enhancement factor of the static spin susceptibility, η
−1, for either region of η>τ
Tc or η<τ
Tc, τ being the relaxation time due to disorder, but with different proportionality constants.
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Katsuhiko Takegahara, Hisatomo Harima, Tadao Kasuya
1985 年 54 巻 12 号 p.
4743-4751
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The standard self-consistent APW band calculations for LaRh
3B
2 and CeRh
3B
2, which crystallize in the hexagonal CeCo
3B
2 type structure, have been done using the local density approximation. Among the 4
f states, the magnetic quantum number
lz=0 state has the large mixing with the conduction bands and thus is the ground state of the crystal field. For CeRh
3B
2, the band calculation, in which the orbital degeneracy of 4
f states is lifted by introducing the
lz dependent pseudo-potential, is also done for the ferromagnetic alignment of the 4
f state with
lz=0. Results show that, due to the large (
ffσ), this 4
f state has strong dispersion along the
c-direction creating 4
f holes on the
Γ-
M-
K plane in the Brillouin zone. This 4
f hole formation is the origin of the anomalous magnetic properties and various anomalous properties are explained consistently on this model.
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Norikazu Ishimura
1985 年 54 巻 12 号 p.
4752-4760
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
A one-dimensional Ising chain with spin-lattice coupling is considered. If the lattice is harmonic but has no translational symmetry, there appears effectively through the spin-lattice coupling a four-spin interaction which decays exponentially with distance. It is shown rigorously that this spin system in the ground state exhibits a devil’s staircase as a function of the exchange parameter
J because of the long range interaction. The ground state phase diagram of the spin system under an external magnetic field is speculated.
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Hirofumi Wada, Yoshitoshi Muraoka, Masayuki Shiga, Yoji Nakamura
1985 年 54 巻 12 号 p.
4761-4766
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The forced volume magnetostriction and magnetization were measured for Fe
65(Ni
1−xMn
x)
35 alloys with 0.05≤
x≤0.33 at 4.2 K up to 48 kOe. With increasing
x, the high field susceptibility, χ
hf, increases rapidly and shows a maximum around
x=0.2, where a long range ferromagnetic order disappears. The analysis of forced volume magnetostriction reveals that a rapid rise of χ
hf is due to an increase of intrinsic band susceptibility around the critical concentration.
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Mitsuhiro Motokawa, Chiaki Uyeda, Akihiro Otsuka, Muneyuki Date, Kazuo ...
1985 年 54 巻 12 号 p.
4767-4775
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Electron paramagnetic resonance (EPR) and antiferromagnetic resonance (AFMR) of copper formate tetrahydrate (Cu(HCOO)
2·4H
2O) is observed at 891 GHz (λ=0.337 mm) by using pulsed high magnetic fields up to 400 kOe. The parameters determined by Yamagata using Seehra and Castner’s AFMR data well explain our experimental results in the antiferromagnetic state. From the temperatures at which linewidths show anomalies, the transition temperatures in high magnetic fields are estimated as
TN(
H)=26±1, 35±5 and 30±2 K for
H0⁄⁄
a″,
b and
c″, respectively. These are fairly high compared with the zero field
TN of 17 K.
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I. P. Zvyagin, Wataru Kinase
1985 年 54 巻 12 号 p.
4776-4782
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The theory of the low-and high field conductivity of ferroelectric ceramics in the region of the positive temperature coefficient of the resistivity (PTCR) is reformulated on the basis of the random barrier model. For the low-field conductivity the model gives the temperature dependence of the conductivity essentially similar to that which follows from the Heywang equivalent-barrier model. The fluctuation of the barrier heights plays an important role for high fields where the shape of the current-voltage characteristic appears to be quite different from that given by the equivalent-barrier model. The experimental data on the high-field conductivity of (BaCe)TiO
3-ceramics are in agreement with the predictions of the random barrier model.
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Naomi Tanba, Mitsuo Wada, Yoshihiro Ishibashi
1985 年 54 巻 12 号 p.
4783-4786
発行日: 1985/12/15
公開日: 2007/05/29
ジャーナル
認証あり
A new ferroelectric phase in BaZnGeO
4 was discovered in a limited temperature range around 230 K. Remanent polarization appears in the plane perpendicular to the unique
c-axis.
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Koichi Kurita, Ken Takiyama, Toshiaki Fujita, Toshiatsu Oda, Atsuhiro ...
1985 年 54 巻 12 号 p.
4787-4793
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Optical absorption due to the phonon forbidden indirect X
6+×R
6− exciton in TlBr has been studied near the fundamental absorption edge by using an electric field modulation method. The electroabsorption (EA) spectrum is analyzed under the approximation of sufficiently weak electric fields. The experimental spectral band shape of EA is explained by the quadratic Stark variation of exciton state for 1s and 2s excitons. It is shown that for the case of 1s exciton the onset of shoulder in the EA spectrum corresponds to the threshold energy of the exciton whereas for 2s exciton the peak of the spectrum corresponds to its threshold energy. Finally, a shift of the 1s exciton state under the applied electric field is estimated to be about 2×10
−3 meV(cm/kV)
2 by the intensity ratio between the EA spectrum and the wavelength derivative absorption one.
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Norimichi Kojima, Ikuji Tsujikawa, Kuniro Tsushima
1985 年 54 巻 12 号 p.
4794-4803
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Absorption spectra corresponding to the
4A2g→
2Eg transition of Cr
3+ in TmCrO
3 were studied. In the lowest energy region,
R exciton lines with Davydov splitting were observed. Temperature and magnetic field dependences of the
R exciton lines suggest that the spin configuration of TmCrO
3 is
Γ2 above 5 K and the coexistence of
Γ2 and
Γ4 below 5 K. In the shorter wave length side of
R lines, satellite bands (
RI′ and
RII′) of electric dipole origin were observed. It is shown that the
RI,II′ bands are the combined excitation of a Cr
3+ exciton and the transition from the ground singlet state to the excited singlet states within the Tm
3+ ground multiplet
3H6, and they are induced by the anisotropic parts of the Cr
3+–Tm
3+ exchange interactions.
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Norimichi Kojima, Ikuji Tsujikawa, Kiyoshi Aoyagi, Kuniro Tsushima
1985 年 54 巻 12 号 p.
4804-4820
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Optical absorption spectra corresponding to the
4A2g→
2Eg transition of Cr
3+ in RCrO
3 (R=Er, Ho, Dy and Tb) were investigated. The exciton lines (
R) with Davydov splitting, and an electric dipole band (
R′) at lower energy side were observed in all compounds. From the temperature and external magnetic field dependences of the
R′ band, it is concluded that the
R′ band in RCrO
3 (R=Er, Ho, Dy and Tb) is the Cr
3+ exciton localized by the magnetostriction which is caused by the R
3+ spin fluctuation or by the static disorder (magnetic domains or magnetic stacking faults) of the R
3+ spin configuration.
In the case of ErCrO
3, besides this
R′ band, a few weak bands were observed in the neighborhood of the
R lines, which correspond to the combined excitation of a Cr
3+ exciton and a Er
3+ spin flip.
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Norimichi Kojima, Ikuji Tsujikawa, Kuniro Tsushima
1985 年 54 巻 12 号 p.
4821-4827
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
Optical absorption spectrum corresponding to the
4A2g→
2Eg transition of Cr
3+ in GdCrO
3 was studied. The
R′ band was observed in the lower energy side of the
R exciton band. The temperature and magnetic field dependences of the
R′ band imply that the
R′ band is the combined excitation of a Cr
3+ exciton and a Gd
3+ spin flip induced by the isotropic part of the Cr
3+–Gd
3+ exchange interaction. As the summary of the successive papers, the classification of the
R′ band in RCrO
3(R=Yb, Tm, Er, No, Dy, Tb and Gd) was undertaken.
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Yoshiyuki Ono, Hiroyuki Ito
1985 年 54 巻 12 号 p.
4828-4840
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The method of canonical transformation is applied in quantizing phonons around a general static solution in a continuum version of a model for t-(CH)
x. The transformed effective Hamiltonian in the perfectly dimerized case is used to calculate the first and second order Raman scattering amplitudes. Especially it is shown that, through the measurement of the second order Raman process, the phonon dispersion can be derived. The application of the formulation to the case with a soliton or a polaron is also discussed.
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Yuzo Mori, Satoru Nakagawa, Masao Matsuoka, Hiroshi Ohkura
1985 年 54 巻 12 号 p.
4841-4850
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
The microwave pulse excitation and subsequent relaxation of the tunneling Li
+ ion in KCl have been studied at 9.4 GHz, using the paraelectric resonance, the microwave saturation recovery and the microwave double resonance (MDR) developed newly. From the MDR, the absorption between
A2u−
T2g in the ground state tunneling quartet is expressed by a line with half-width of 0.6 GHz peaked at 8.5 GHz. The energy relaxation time
Tb depends on the thickness of specimen
L and temperature
T as
Tb(msec)\simeq
L(cm)·
T(K). Abrupt decrease of
Tb is found when the specimen is immersed in He II. These data are explained in terms of the bottleneck effect of resonant phonon (RP) emitted from the microwave pumped system. The lifetime
Tph of the RP is governed by its extinction at a two-level system on the surface with a rate of 0.01/reflection. The relation
Tb=
Tph is derived after reducing the quartet to doublet.
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Naohisa Wada, Mitsuo Honda, Hideo Suzuki
1985 年 54 巻 12 号 p.
4851-4860
発行日: 1985/12/15
公開日: 2007/06/01
ジャーナル
認証あり
In order to understand the molecular mechanism of firefly bioluminescence, the observed absorption spectra of
D-(−)-luciferin (LH
2) and dehydroluciferin (L) in acidic or basic solution are reproduced by the LCAO-ASMO-SCF-CI calculation on π-electrons.
It is thus found that the first absorption band of LH
2 in basic solution is ascribable to the intramolecular charge-transfer from benzothiazole to thiazoline ring, and that this absorption band is considerably affected by the reaction field due to solvent medium. On this basis, we discuss the formation process of the excited state of oxyluciferin (oxy-L) caused by the oxidation of LH
2, together with CIEEL (Chemically Initiated Electron Exchange Luminescence) mechanisms proposed by several investigators.
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