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Yoshimi Tsuchiya, Shigetake Horie
1985 Volume 54 Issue 1 Pages
1-4
Published: January 15, 1985
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We have investigated the pattern formation of the Williams domain when a super-critical voltage is suddenly applied to a thin layer of a nematic liquid crystal. Analyzing about two-hundred paths of an order parameter which represents the degree of the ordering of the pattern, we have clarified the transient behavior of the most probable path and the fluctuation. It has been found that the evolution process of the Williams domain is well described by a scaling function and fluctuation enhancement takes place in a middle stage of the evolution.
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Hidenori Hasimoto, Tsutomu Kambe
1985 Volume 54 Issue 1 Pages
5-7
Published: January 15, 1985
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The equilibrium form of a thin elastic rod of circular cross section with the bending stiffness
A and torsional rigidity
C is found to simulate the shape of a motion of thin vortex filament rotating with a constant anglar velocity
Ω and translating with a constant velocity
V and slipping along the filament with a constant speed
c, obeying the so-called local induction equation. We have only to satisfy
Ω0C=
Ac,
T0=
AΩ and
M0=
AV,
where the constants
T0,
M0 and
Ω0 corresponding respectively to the internal stress, the moment on the cross-section and the torsion angle per unit length are determined by the boundary conditions.
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Ryuji Takaki
1985 Volume 54 Issue 1 Pages
8-10
Published: January 15, 1985
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Partial differential equations, which govern flows in a Hele Shaw type cell, are derived, where flows are driven by deforming one side wall made of an elastic plate or a pliant membrane. The equations are similar to the diffusion equation but contain a cubic or a square of the Laplacian operator. Possibilities are suggested to apply these equations to fundamental researches of some recent problems, such as the physiolosical micro-circulation, the liquid-crystal device for computer and the cell biology.
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Masayoshi Taguchi
1985 Volume 54 Issue 1 Pages
11-14
Published: January 15, 1985
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The wave-induced current by electron cyclotron resonance heating (ECRH) is investigated in an axisymmetric toroidal plasma. The plasma is assumed to be so weakly relativistic that the only relativistic correction to the resonance condition is considered. The effect of trapped electrons are also calculated to the order of \sqrtε, where ε is the inverse aspect ratio. The trapped electrons and the relativistic resonance condition are shown to have important effect on the efficiency of current drive by ECRH.
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Mitsuru Yamagiwa, Masahiro Wakatani, Yuji Nakamura
1985 Volume 54 Issue 1 Pages
15-18
Published: January 15, 1985
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Linear stability against low m interchange modes are studied for the pressure profile having a sharp peak in the central region. In the current-free high β plasmas of Heliotron E, density fluctuations having odd asymmetry around the central chord are observed after the pellet injection which produces such a pressure profile.
It is shown that the m=1/n=1 and m=3/n=2 modes become candidates to explain the experiments. Nonlinear behaviors of the same modes are also discussed.
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Masayoshi Tajiri, Mutumi Tuda
1985 Volume 54 Issue 1 Pages
19-22
Published: January 15, 1985
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This letter is concerned with existence conditions for ion acoustic solitons in a plasma with negative ions. It is shown that large Mach number potential-well solitons can be in existence in a certain parameter region.
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Masanori Aoki, Yoshinori Tabata
1985 Volume 54 Issue 1 Pages
23-24
Published: January 15, 1985
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Interaction of a soliton with a mass impurity is investigated in the Toda lattice by means of computer simulation. The energy of the localized mode
Eloc is calculated as a function of the incident soliton energy
Ein. The decrease of
Eloc with increasing
Ein is observed for the cases of mass ratio around 0.09 and 0.18.
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Michisuke Kobayashi, Tohru Takahashi
1985 Volume 54 Issue 1 Pages
25-28
Published: January 15, 1985
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The collective excitation modes in an alkali metal intercalated transition metal dichalcogenide,
e.g., Li
xTiS
2, consisting of alternating layers of electrons and alkali ions are investigated. Two kinds of structure factors are introduced. One is concerned with the structure of the same kind of carriers and the other with the structure of a different kind of carriers. The obtained dispersion equation has the same form as that of the electron-hole system in type II semiconductor super-lattices. The theory suggests the possibility of existence of acoustic plasma modes.
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Mitsuo Kataoka
1985 Volume 54 Issue 1 Pages
29-32
Published: January 15, 1985
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A non-phononic mechanism based on Geilikman’s model is proposed for the superconductivity of the A15 compounds with high transition temperatures
Tc. The band structure near the Fermi level ε
F in these compounds is characterized by coexsistence of the very narrow
Γ12-subbands called the ‘d-bands’ and other wide bands called the ‘s-bands’. The Coulomb interaction between the s- and d-electrons causes an indirect attractive interaction between the s-electrons via the particle-hole pair excitation in the d-electron system. The superconductivity in the s-electron system forces the d-electrons to form Cooper pairs. The structural phase transition redistributes the d-electrons to go away from ε
F, being unfavourable in the superconducting phase. This model can explain successfully the interference of the superconductivity with the structural transition observed in V
3Si and Nb
3Sn.
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Katsufumi Hashimoto
1985 Volume 54 Issue 1 Pages
33-36
Published: January 15, 1985
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It is shown that a spin density wave (SDW) Hartree-Fock (HF) state corresponds to the low-spin ground state in almost half-filled Hubbard systems with infinite repulsion. The SDW HF state has a long range ferromagnetic spin ordering. This suggests that the low-spin ground state does not indicate absence of ferromagnetism.
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Tadataka Morishita, Yuji Togami, Kuniro Tsushima
1985 Volume 54 Issue 1 Pages
37-40
Published: January 15, 1985
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Compositionally modulated films have been prepared by alternate deposition of Fe and Gd atoms. The films with each layer thickness of more than ∼30 Å show a new magnetic layer structure having a “compensation temperature”. The observed temperature dependence of magnetizations has been understood by considering independent contributions from the Fe and Gd regions. The sample with the shortest periodicity of the modulation (Fe 9 Å/Gd 11 Å), presents the magnetization vs temperature relation quite similar to a coevaporated amorphous film of Gd
30Fe
70.
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Satoru Watanabe, Yoshihito Abe, Ryozo Yoshizaki
1985 Volume 54 Issue 1 Pages
41-44
Published: January 15, 1985
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The proton spin-lattice relaxation rate 1⁄
T1 in solid thioacetamide were measured between 28.5 K and 200 K at two Larmor frequencies, 11.4 MHz and 25 MHz. The temperature dependence of 1⁄
T1 was characterized by three maxima, two maxima observed around 90 K and 37 K showing the frequency dependence and the frequency independent one at 44 K. Taking into account two crystal-lographically inequivalent thioacetamide molecules, the temperature and Larmor frequency dependence of 1⁄
T1 was explained by the contribution from the quantum mechanical and classical limit of tunneling rotation of the methyl groups around their
C3 axes.
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Yoshimasa Matsuno
1985 Volume 54 Issue 1 Pages
45-50
Published: January 15, 1985
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It is shown that the Bäcklund transformation of the Benjamin-Ono equation due to Bock and Kruskal (Phys. Lett.
74A (1979) 173) is derived from that due to Nakamura (J. Phys. Soc. Jpn.
47 (1979) 1335).
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Hitoshi Harada, Shin’ichi Oishi
1985 Volume 54 Issue 1 Pages
51-56
Published: January 15, 1985
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A method is presented to pick out candidates for completely integrable nonlinear partial differential equations among those in the same form but with their coefficients being different in value. This method is based on the singularity analysis of Weiss
et al. As an example, the fifth order KdV type equations are investigated. Investigations of various forms of nonlinear partial differential equations by this method will be of some help to the systematic study of the complete integrability.
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Tsutomu Kawata
1985 Volume 54 Issue 1 Pages
57-63
Published: January 15, 1985
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Assumming the potential on a compact support, we simply show that fundamental matrix solutions analytic on the upper and lower planes of the spectral parameter approach to triangular matrices as
x→±∞. After the normalization of fundamental solutions by the triangular states, the scattering matrix and R–H problem are naturally defined through triangular factorization formulae. A derivation of the Gel’fand-Levitan integral equation is given based on the R–H problem.
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M. Lutzky
1985 Volume 54 Issue 1 Pages
64-68
Published: January 15, 1985
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It is shown that a non-canonical symmetry of a finite-dimensional Hamiltonian system leads to a bi-Hamiltonian structure for the system. If the recursion operator has a vanishing Nijenhuis tensor and minimal degeneracy, it generates a sequence of conserved quantities in involution. The recursion operator is also the Lax matrix of an isospectral representation, and its eigenvalues are conserved quantities in involution. If these conserved quantities are functionally independent, the system is completely integrable.
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Masahiro Nakagawa, Tadashi Akahane
1985 Volume 54 Issue 1 Pages
69-80
Published: January 15, 1985
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A molecular statistical theory of smectic A liquid crystalline mixtures is presented. Both the intermolecular repulsions and the attractions are consistently introduced in similar to the previous work on smectic A liquid crystals. The repulsive interaction is approximated in terms of the hard-core potential and is taken into account within the second-virial approximation. The temperature dependence of the order parameters over the smectic-nematic (or isotropic) and nematic-isotropic phase transitions is numerically calculated for several binary mixtures. In addition the phase diagrams of them are constructed. The smectic-nematic (or isotropic) transition temperatures in binary mixtures tend to be increased in comparison with the predicted values in terms of the linear approximation, being consistent with some experimental findings. It is also found that the symmetry-breaking component of one-body pseudo-potential contributes to the thermal stability of smectic A phase in smectic A binary mixtures.
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Katsumi Kose, Kozo Satoh, Tamon Inouye, Hiroshi Yasuoka
1985 Volume 54 Issue 1 Pages
81-92
Published: January 15, 1985
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The present study describes a method for measuring a spatial distribution of flow velocity in fluid. This method employs two selective irradiation pulses; the first pulse is used for selective saturation and the second pulse is used for selective observation. To image flowing fluid correctly, images are reconstructed from a set of second echoes in a pulse sequence similar to Carr-Purcell-Meiboom-Gill sequence. The velocity image is computed using two images; one is that of the nuclear spin density and the other is that with 100 msec delay time between the two selective irradiation pulses. The obtained velocity distribution of water in a circular pipe is parabolic and agrees well with that of Poiseuille flow, which has proved the method developed here of great use in the study of fluid flow.
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Katsumi Yonei
1985 Volume 54 Issue 1 Pages
93-101
Published: January 15, 1985
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One-electron energy levels of atoms are calculated for an effective potential obtained from the relativistic (
Remark: Graphics omitted.) model proposed by Tomishima. Use is made of Moore’s approximation method to solve the Dirac equation. Through a detailed comparison of the results with those of the SCF calculations as well as those of experiment, it is shown that the present calculation gives quite satisfactory results over a wide range of levels and atomic species. The agreement of the calculated and experimental energies is particularly good as to electrons bound in the inner region of an atom. Although the agreement with experiment is less close for outer electron energies, the present calculation still gives a reasonable estimate of them.
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Susamu Taketomi
1985 Volume 54 Issue 1 Pages
102-107
Published: January 15, 1985
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Using the stress tensor expression for liquid crystals (nematics) and with two approximations, we obtain the same stress tensor as that for magnetic fluids with an intrinsic angular momentum obtained by Shliomis and independently by Tanahashi
et al. The two approximations consist of neglect of the terms higher order than the second in a director
n and neglect of the terms which originate from distortion energy. We also make clear through these approximation procedures that Shliomis and Tanahashi
et al.’s formula involve the assumptoin of noninteraction between colloidal particles in the magnetic fluids.
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Norihiko Nakauchi, Setsuko Sega
1985 Volume 54 Issue 1 Pages
108-120
Published: January 15, 1985
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Dynamical equations for the power spectra of turbulence energy, heat flux and temperature variance are formulated by applying the modified 0–4th-cumulant approximation, and are numerically solved at moderate Reynolds number 32 and Prandtl number unity. Results are compared with the theoretical prediction and experiment by Sirivat & Warhaft (J. Fluid Mech.
128 (1983) 323). In particular the evolution of temperature variance 〈θ
2〉 and heat flux 〈θ
w〉 in the direction of a linear mean temperature gradient agree well with their theoretical predictions 〈θ
2〉∝
t2−t and 〈θ
w〉∝
t1−t. (
n is the decay exponent of the turbulence energy 〈
q2〉⁄2∝
t−t.) Moreover temperature and heat flux transfer spectra are shown; they are essential to understand these turbulent fields.
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Osamu Inoue
1985 Volume 54 Issue 1 Pages
121-133
Published: January 15, 1985
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Two-dimensional, turbulent mixing layers with initial periodic forcing are simulated by a vortex blob method. The motions of up to 2600 vortices and 3000 marker particles are followed by the use of the direct summation method. The first-order accurate Euler scheme is employed as a time-integral scheme. Forcing frequencies higher than the first subharmonic of the predominant, frequency of an unforced mixing layer are applied. It is shown that the development of a turbulent mixing layer depends much on forced disturbances and that turbulence suppression or amplification occurs depending on forcing frequencies. The results are consistent with experiments.
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Yoshio Saito, Jiro Mizushima, Naoyuki Futami
1985 Volume 54 Issue 1 Pages
134-145
Published: January 15, 1985
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Statistical properties of magneto-hydrodynamic turbulence are investigated theoretically using the modified zero-fourth cumulant approximation. A set of two dynamical equations for kinetic and magnetic energy spectra is integrated numerically for Prandtl number unity. The equipartition between kinetic and magnetic energy spectra is shown to be attained in high wavenumbers after a short elapse of time, but a significant difference between them is found in low wavenumbers. The energy spectrum of the form
k−3⁄2 predicted by Kraichnan is not confirmed from our numerical results. Statistical quantities such as the total energy, the enstrophy and the micro-scale Reynolds number are calculated from the energy spectra. A phenomenological theory is also developed to obtain a decay law of the total energy and it is compared with the results of the numerical calculations.
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Satoru Iizuka, Koichi Saeki, Noriyoshi Sato, Yoshisuke Hatta
1985 Volume 54 Issue 1 Pages
146-151
Published: January 15, 1985
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Effects of stationary electrons on the Buneman instability in a bounded electron beam-plasma system are investigated theoretically and experimentally. The Buneman instability is generated in a low-beam-current regime and is coupled with the Pierce instability in the high-beam-current regime. The threshold current of the Buneman instability is considerably increased by introducing a small amount of stationary electrons into the system.
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Kazuo Saitoh
1985 Volume 54 Issue 1 Pages
152-161
Published: January 15, 1985
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Depth profiles of nuclear-encounter probabilities of planar channeled protons in CaF
2 and BaF
2 are studied. For the analysis of the experimental results, time evolution of the spatial distribution of ion flux in the planr channel is simulated. In the simulation a continuum planar potential derived from the ion-ion interaction potentials is used and the momentum fluctuation due to scattering with electrons and thermally vibrating atoms is taken into account. From the depth dependence of the flux distribution, the nuclear-encounter probabilities are obtained, which are in good agreement with the experimental results obtained by backscattering and nuclear reaction measurements.
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Naoyuki Tokuda
1985 Volume 54 Issue 1 Pages
162-167
Published: January 15, 1985
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This paper presents a finite-difference solution of a crystal growth Stefan problem in an isothermal binary component melt system. To ensure the accuracy of the computation without increasing the computational time, a variable scheme of grid size has been introduced whereby a smaller grid size is chosen at small times when the effective number of grid points available for computations is small. The numerical results are obtained for several values of the equilibrium parameter
ue of the problem. The present results confirm that both the small time Lagrange-Bürmann solution and the large time asymptotic solution of the same problem given earlier by the author predict a correct behavior of the solution over considerably extended physical time domains. An excellent experimental verification is also obtained.
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Shûzi Harada, Tôru Kasahara, Shigeru Tamaki
1985 Volume 54 Issue 1 Pages
168-174
Published: January 15, 1985
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Shear and Young’s modulus of hydrogenated Pd alloys have been measured as a function of temperature and hydrogen-concentration. From these measurements, the bulk-modulus was calculated in order to evaluate the harmonic term of lattice energy. The anharmonic term was also obtained from the measurement of thermal expansion. The value of harmonic term decreases with increasing hydrogen-concentration. The anharmonic term is slightly changed by hydrogenation. These behaviors were interpreted on the basis of the electron theory.
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Eizaburo Kanda, Terutaka Goto, Hiroshi Yamada, Shozo Suto, Satoshi Tan ...
1985 Volume 54 Issue 1 Pages
175-185
Published: January 15, 1985
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Low temperature behavior of elastic constants (
C11−
C12)⁄2,
C44 and
C11 of NaCl crystals with OH impurity ions of various concentrations up to 650 ppm has been studied by means of an ultrasonic method. Pronounced softenings of the elastic constants below 50 K with minimum points around 0.8 K have been observed. The interaction between the elastic strain and the quadrupolar moments of the quantum tunneling states of an OH ion was found to be essential for the elastic anomalies. A variational method was employed to obtain the tunneling states of an OH ion in an off-center potential, and the quadrupolar moments of the states were calculated. The linear response theory for the quadrupolar moments has been adopted to explain the softening of the elastic constant.
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Hiroshi Kameyama
1985 Volume 54 Issue 1 Pages
186-195
Published: January 15, 1985
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The contribution of piezoelectricity was taken into consideration in the elastic wave equation referred to the rotated coordinates, and investigated for all of the pure and semipure mode directions in the crystals of the piezoelectric point groups. In the point groups belonging to cubic, tetragonal I, trigonal I, orthorhombic, monoclinic and triclinic systems, pure and semipure mode directions are determined similarly to the case of neglecting the piezoelectric effect. In the points groups belonging to trigonal II, tetragonal II and hexagonal systems, it is found that the piezoelectric effect shows a remarkable contribution to pure and semipure mode directions. The pure and semipure mode directions can be derived taking account of the crystal symmetry elements.
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Akira Terai, Hiroyuki Ito, Yoshiyuki Ono, Yasushi Wada
1985 Volume 54 Issue 1 Pages
196-202
Published: January 15, 1985
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Linear modes around the polaron solution are analyzed numerically in the model of Takayama, Lin-Liu, and Maki, which is a continuum model of
trans-polyacetylene (CH)
x. The polaron generates five localized phonon modes, one of which with ω≅0 corresponds to the Goldstone mode. The phase shifts of extended phonon modes are obtained, which show that effective potential for them is reflectionless. The creation energy of a single polaron is found to be \sqrt2
Δ0⁄π−0.80ω
0, the second term being the quantum correction and
Δ0 and ω
0 denoting the half of the gap in the electronic energy spectrum and the frequency of the optical phonon with vanishing wave number, respectively, in the uniformly dimerized state.
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Kêitsiro Aizu
1985 Volume 54 Issue 1 Pages
203-210
Published: January 15, 1985
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A thermodynamical theory is presented of the transition sequence [prototypic→ferroic→ferroic] where the two ferroic phases have the same symmetry. The so-called “two-sublattice model” is not adopted; instead, an order parameter in the ordinary sense is employed (it is denoted by
Q). In the free energy function, the eighth-degree term, which has conventionally been ignored, is given a due regard. It plays a vital role. The conditions for the equisymmetric ferroic-to-ferroic transition to occur are found. The transition temperature and transition pressure are determined. The temperature range of each ferroic phase under a constant pressure and the
Qs vs
T relation over the whole of that range are deduced, with the use of the mathematics of cubic equations.
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Shoji Kashida, Koichi Sano, Toshiro Fukumoto, Hiroyuki Kaga, Masahiro ...
1985 Volume 54 Issue 1 Pages
211-219
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The successive structural phase transitions in a linear chain compound (CH
3)
3NHCdCl
3 were investigated by an X-ray photographic method. From the intensities of the super lattice reflections, the structures of the monoclinic (3×2) phase which has P2
1/m symmetry and the hexagonal (3×3) phase which has P6
3/m symmetry were discussed.
Present analysis shows that the phase transitions of this compound are fairly well described by a sequence of rigid reorientations of the metal-chlorine chains. It was also argued that the (3×3) phase would be composed of micro twins.
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Toshifumi Taniguchi, Yoshihito Miyako, J. L. Tholence
1985 Volume 54 Issue 1 Pages
220-230
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The nonlinear susceptibility, χ
2, has been observed on the amorphous spin glass Fe
10Ni
70P
20 using a Hartshorn bridge. The critical exponents γ
s=2.3±0.2 and δ=5.2±0.5 were estimated from the expressions χ
2∼ε
−γs (ε=|(
T−
Tg)⁄
Tg|) above
Tg and χ
2∼
h02⁄δ−2 at
T=
Tg (
h0 is ac-field amplitude), which tend to confirm that the spin glass transition is characterized by critical exponents different from those of the mean field theory. The HT-phase diagram has also been determined from the anomalies of the transverse nonlinear susceptibility; χ
2⊥. In the presence of a longitudinal static magnetic field, χ
2⊥ splits into one peak and a broad maximum with increasing the longitudinal static magnetic field. The temperature of the low temperature peak corresponds to the onset of strong irreversibility and can be assigned to the AT line, while the maximum corresponds to the GT line. These data confirm the phase diagram recently deduced by others from χ
0⊥.
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Toshiaki Saito, C. J. Sandberg, Yoshihito Miyako
1985 Volume 54 Issue 1 Pages
231-235
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The frequency dependence of the imaginary part Im χ
0(ω) of the dynamical susceptibility on a spin glass compound (Ti
0.9V
0.1)
2O
3 was investigated at 1 Hz∼240 Hz. The Im χ
0(ω) is well fitted to the relation that Im χ
0(ω)∼ω
ν in the frequency range measured. When the temperature is decreased, the exponent ν changes remarkably from about 1.0 to nearly zero for 0.8<
T⁄
Tg<1.1. The spin autocorrelation function changes from the exponential decay, exp (−
t⁄τ) at
T>>
Tg to the algebraic decay,
t−ν at
T\lesssim
Tg. At
Tg, ν is 0.19, which differs from the predicted value 0.5 of the recent mean-field dynamical theories for spin glasses. The noticeable change in ν is, however, qualitatively consistent with the theories. We also found that the variation in ν coincides with that in β, where β is the measure of the width of the distribution of relaxation times.
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Hatsuhiro Kato
1985 Volume 54 Issue 1 Pages
236-244
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A study is made of nonlinear waves which appear on the surface of a
4He film when the film loads electrons on its surface. By using the reductive perturbation method it is found that the nonlinear waves obey the Benjamin-Ono equations or the Korteweg-de Vries equation according to the conditions imposed on the system.
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Hisashi Hiramoto, Yutaka Toyozawa
1985 Volume 54 Issue 1 Pages
245-259
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The system of two electrons coupling with phonon fields is studied with the use of the path integral method. In particular, the condition of the formation of a bipolaron and its physical properties are investigated in detail. The deformation potential interaction with acoustic phonons (the coupling constant
Sac) and the Fröhlich interaction with optical phonons (
Sop) act to help the bipolaron formation against the direct Coulomb repulsion which prevents it. Usually,
Sac plays a dominant role. With ε
∞⁄ε
0<<1 and the optical phonon energy not so large compared with the electron band width, however, the bipolaron can be formed at large values of
Sop even when
Sac=0. The bipolaron always has an enormous effective mass; thus it is practically localized. The mean distance between two electrons in the bipolaron is usually of the order of the interatomic distance.
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Jun-ichi Igarashi
1985 Volume 54 Issue 1 Pages
260-268
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Electron correlation is studied in the special case of a single reversed spin in an otherwise fully aligned band in the one-dimensional Hubbard model for the purpose of examining our previous theory which exactly takes account of the three-body correlation. The importance of the three-body correlation is demonstrated through a comparison of our results with those of exact theories. The ground-state energy and the single particle spectra are in good agreement with McGuire-Lieb-Wu’s exact solution and also with exact numerical solutions for finite size systems over a wide range of the intraatomic Coulomb integral and the electron number. The properties of the ground state are studied in detail through the calculation of pair correlation functions.
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Hiroaki Hazama, Yasuo Itoh, Chihiro Hamaguchi
1985 Volume 54 Issue 1 Pages
269-277
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Shubnikov de Haas oscillations in the longitudinal magnetoresistance were measured in Te doped n-GaSb in the temperature range from 4.2 to 20 K in magnetic fields up to 8 Tesla. From the analysis of oscillation amplitude as a function of temperature the conduction band edge mass and Dingle temperature were estimated to be 0.041
m and 7.5 K, respectively. Measurements at magnetic fields up to 30 Tesla at 4.2 K reveal the spin-splitting, from which the effective
g factor of GaSb was estimated to be
g=−7.68±0.1. The energy band for GaSb was calculated throughout the entire Brillouin zone and the analysis of the energy band parameters for GaSb was carried out using the
k·
p perturbation method. These results are found to be consistent with the experimental values, such as the effective mass and the effective
g factor determined from Shubnikov de Haas measurements.
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Hidenori Morita, Masuo Fukui, Osamu Tada
1985 Volume 54 Issue 1 Pages
278-281
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Aers and Boardman have claimed that it would be very difficult to experimentally observe an attenuated total reflection (ATR) mode of multiple surface plasmon polaritons (MSP’S) in the otto configuration (prism-vacuum-Al). we have reinvestigated ATR spectra of MSP’s in the Otto geometry by using a bulk-selvedge coupling theory developed by Sipe. Numerical calculation clearly shows that the experimental observation of ATR resonance due to the MSP’s is feasible when the thickness of the vacuum gap between the prism and Al is properly chosen.
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Yasuhiro Ohkawa, Toshio Nishida, Masao Nagase, Takeo Ichinokawa
1985 Volume 54 Issue 1 Pages
282-288
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Angle-intensity profiles of inelastically scattered electrons were measured around several diffraction spots for the energy loss less than 20 eV. Peak structures were observed near diffraction spots. The energy loss dependence and the incident energy dependence of the peak position are discussed on the basis of the two step inelastic diffraction model, which suggests three characteristics in electron energy loss processes at a surface: (1) maximum probability of surface electronic excitation occurs at the momentum transfer parallel to the surface, (2) peaks due to loss before diffraction process dominate for grazing incidence and (3) a part of inelastic electrons due to surface electronic excitations have coherency as well as the incident electron according to the spot-like distribution of inelastic electrons.
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Masahiro Isino, Katsumi Akutsu, Yoshio Muto
1985 Volume 54 Issue 1 Pages
289-297
Published: January 15, 1985
Released on J-STAGE: June 01, 2007
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The effects of iron impurities up to 8 at% and of tantalum ones up to 10 at% on superconductivity is studied. The concentration dependence of various superconducting properties such as
Tc and d
Hc2⁄d
T|
Tc changes at a few at% of solute concentration. This is ascribable to the substantial overlap of the Friedel oscillation of the conduction electron density around each solute atom; the overlap affects the cencentration dependence of properties such as the electronic density of states at the Fermi energy and the electronic diffusion constant and then of superconducting properties.
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Takuma Ishikawa, Haruo Yoshida
1985 Volume 54 Issue 1 Pages
298-303
Published: January 15, 1985
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The transverse component of the dynamic form factor of the two-dimensional dilute Ising-like ferromagnet with nearest neighbor exchange interactions at absolute zero temperature is obtained by using a perturbation method developed by the authors. The dynamic form factor has a five-peak structure for every wave number and concentration. The dynamic form factor for finite-size systems is also calculated by a computer. The results obtained by the perturbation theory are in fairly good agreement with those for finite-size systems.
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Yoshichika \={O}nuki, Yoshiaki Shimizu, Takemi Komatsubara
1985 Volume 54 Issue 1 Pages
304-311
Published: January 15, 1985
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We have measured the electrical resistivity, magnetoresistance, magnetic susceptibility and magnetization of CeCu
6 in the temperature region of 0.6 K to room temperature. The magnetic property is extremely anisotropic, reflecting the orthorhombic crystal structure. The anisotropy of negative magnetoresistance can be qualitatively understood by the corresponding magnetization. We have found that CeCu
6 is a typical Kondo lattice substance, having no magnetic ordering. The Kondo temperature is estimated as 2–3 K.
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Yoshikazu Ishikawa, Norio Saito, Masatoshi Arai, Yuji Watanabe, Humihi ...
1985 Volume 54 Issue 1 Pages
312-325
Published: January 15, 1985
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Magnetic properties of (1−
x)Fe
2TiO
3-
xFe
2O
3 with
x near the percolation threshold
x∼0.2 have been studied by using single crystals. It has been found that 0.9FeTiO
3-0.1Fe
2O
3 exhibits typical characteristics of the cluster spin glass, while 0.79FeTiO
3-0.21Fe
2O
3 can be identified with the re-entrant spin glass. Referring to the neutron scattering data obtained for those compounds, the magnetic phase diagram has been determined. The results have been discussed based on the current theories on the concentrated spin glass systems.
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Katsuhiko Suzuki, Yoshika Masuda
1985 Volume 54 Issue 1 Pages
326-333
Published: January 15, 1985
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The volume magnetostriction and magnetization in the itinerant electron ferromagnetic Ni
3Al system have been measured. The magneto-elastic coupling constant
D(
T) at temperature
T shows a
T4⁄3-dependence in a temperature range below
Tc.
D(
T) is calculated by using the self-consistent renormalization (SCR) theory of spin fluctuations, which explains experimental results well. The shift of the Curie temperature
Tc with pressure
P, d
Tc⁄d
P is calculated in the same way. The estimated value of d
Tc⁄d
P by employing the present experimental results of magnetization and volume magnetostriction agrees very well with the experimental one by Buis
et al. The
Tc-dependence of d
Tc⁄d
P is also discussed by using the present calculated result.
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Takeshi Kanomata, Kiwamu Shirakawa, Takejiro Kaneko
1985 Volume 54 Issue 1 Pages
334-338
Published: January 15, 1985
Released on J-STAGE: May 29, 2007
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The pressure derivative of the Curie temperature d
Tc⁄d
p of FeCr
2S
4 and CoCr
2S
4 has been obtained from the results of temperature dependence of initial permeability under pressure up to 7 kbar. For both compounds, the Curie temperature increases linearly with pressure and d
Tc⁄d
p is found to be equal, the values of which are 0.5 K/kbar. The isothermal compressibility of CoCr
2S
4 has also been studied by means of high-pressure X-ray diffraction techniques. On the basis of these results, the exchange mechanism of ferri- and ferromagnetic chalcogenide spinels is discussed.
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Hideki Yoshiyama, Kazuko Motizuki
1985 Volume 54 Issue 1 Pages
339-347
Published: January 15, 1985
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The temperature-induced helix-antiferro transition of NiBr
2 is studied on the basis of the self-consistent harmonic approximation. The semi-polar representation is used to take into account the spin fluctuation effects quantum-mechanically. The calculated temperature dependence of the pitch of the helical structure in NiBr
2 is in good agreement with the observation. The estimated transition temperature from the helix to the antiferro is 19.6 K which is compared with the observed value of 22.8 K. The thermal average of a spin has been calculated and compared with the observation. The spin contraction at
T=0 K is obtained to be 0.054.
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Yuji Ito, Masakazu Nishi, C. F. Majkrzak, L. Passell
1985 Volume 54 Issue 1 Pages
348-357
Published: January 15, 1985
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Polarized neutron powder diffraction and high resolution powder neutron diffraction measurements with the unpolarized beam were performed in an attempt to determine the low temperature magnetic and crystal structure of CsFeS
2. The results of the measurements reveal that the magnetic and the crystal structure of the low temperature phase as well as the transition behavior depend strongly on the state of the internal stress of the sample. Using a powder sample of the stress free as-grown fine crystallites, we determine the low temperature crystal structure as a triclinic one with lattice parameters at
T=40 K as
a=7.08 Å,
b=12.05 Å,
c=5.47 Å, α=96.6°, β=100.9°, γ=88.5°. The results also suggest that the observed transition may be viewed as that of the Spin-Peierls singlet to the Néel state, which accompanies the simultaneous structural transformation.
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Hiroyasu Egashira, Hidenori Kubo, Norikiyo Uryû
1985 Volume 54 Issue 1 Pages
358-362
Published: January 15, 1985
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The hyperfine field of Cu nuclei has been investigated theoretically with the use of the molecular orbitals for the cluster of central Cu
2+ ion and the surrounding ligands. According to the previous experimental studies, the hyperfine field of Cu nuclei as well as the
g-factors vary linearly with
n, the number of Br
− ions in the surrounding ligand sites. Such linear dependences have been reasonably explained and have turned out to be due to the difference between the unpaired spin densities of Cl
− and Br
− ions as well as the difference between the overlap integrals of Cu
2+–Cl
− and Cu
2+–Br
− ions.
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Hiroaki Kadowaki, Koji Ubukoshi, Kinshiro Hirakawa
1985 Volume 54 Issue 1 Pages
363-373
Published: January 15, 1985
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Neutron elastic and inelastic scattering experiments on VBr
2 single crystals have been performed to study magnetic properties of the
S=3⁄2 Heisenberg triangular-lattice antiferromagnet. Bragg intensities are consistent with the Néel (120°) structure having average moment 〈
S〉⁄
S=83±5% in the
a-
c plane. The dispersion relations show a two-dimensional character and are described by the spin-wave theory with exchange constants
J=16 K and
J′=0.2 K. A preliminary inelastic measurement on VCl
2 gives
J=22 K and
J′=0.1 K. The magnetic diffuse scattering observed in the previous powder pattern is found to be inelastic. The unusual decrease of magnetic Bragg intensities with lowering temperature is attributed to the polarization of
51V nuclear spins due to hyperfine interaction.
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