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Hideki Yamazaki, Shoichi Kai, Kazuyoshi Hirakawa
1987 年 56 巻 1 号 p.
1-4
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Creation-annihilation process of defects in WD rolls of a nematic liquid crystal was studied experimentally as an electrohydrodynamic instability of a layer within two free lateral side-walls of relatively large aspect ratio. A regular pattern was seen to be formed through creation and annihilation of defects. The defects began to move fast as they approach to the side-walls. Their motion changed from gliding (across roll-axis) one to climbing (along roll-axis) one with time. Finally the defects disappeared through climbing motion.
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Mitsuaki Ginoza
1987 年 56 巻 1 号 p.
5-8
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
For the hard-sphere Yukawa system, the modified mean spherical model is defined and the exact solution of Ornstein-Zernike equation for this model is presented. The result suggests that the effect of background charge on the static structure of the system is significant.
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Yasuhiro Akutsu, Noriko Akutsu
1987 年 56 巻 1 号 p.
9-12
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
A method to calculate the equilibrium crystal shape is presented, which is based on the numerical (Monte-Carlo) evaluation of the Andreev’s Legendre-transformed interface free energy. The method is applied to draw the equilibrium shape of the two-dimensional absolute solid-on-solid models.
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Takashi Matsuo, Nobuo Kobayashi, Yozaburo Kaneko
1987 年 56 巻 1 号 p.
13-16
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Time-of-flight energy spectra of Ar atoms produced through charge transfer reactions in collisions of Ar
+(metastable Ar
M+) ions with Ne atoms have been measured at a collison energy of 50 eV. Two prominent peaks appear at exoergicities of about 0.35 and 1 .5 eV. The measurement of the appearance energies of these peaks suggests that the 0.35 eV peak is due to metastable 3d′
2F
7⁄2 ions and that the 1.5 eV peak is an indication of the existence of an unknown long-lived excited Ar
+ state.
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Tetsuo Koizumi, Takashi Tsurugai, Iwao Ogawa
1987 年 56 巻 1 号 p.
17-20
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
An injected-ion drift tube mass spectrometer, whose drift tube can be cooled with liquid nitrogen, was developed for studying the mobilities of ions in low-temperature gases. The mobilities of Kr
++ in Kr were measured at 88 K with this apparatus as a function of the reduced field
E⁄
N ranging from 30 to 280 Td. It was found that the Kr
++ ions have four distinct mobilities in the
E⁄
N range below about 70 Td. These mobilities were identified as being associated with Kr
++ ions in the four different electronic states,
3P
2,
3P
1,
3P
0 and
1D
2.
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Shinji Kawaji, Junichi Wakabayashi
1987 年 56 巻 1 号 p.
21-24
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Scaling relation of the diagonal and the Hall conductivities is experimentally studied in the (0↓+) Landau level (0 refers to Landau quantum number, ↓ to antiparallel spin to the magnetic field, + to lower valley) of an
n-channel inversion layer on a silicon (001) surface in magnetic fields of 13 T and 15 T at temperatures between 1.5 K and 4.2 K.
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Sadamichi Maekawa, Yoshimasa Isawa, Hiromichi Ebisawa
1987 年 56 巻 1 号 p.
25-28
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The conductance fluctuation in small metallic systems is sensitive to the sample geometry and the size and position of leads. We formulate the fluctuation by taking into account the sample geometry as a four-terminal network. It is shown that the conductance fluctuation increases dramatically as the distance of the voltage terminals decreases. Recent experimental results for metallic wires support our theoretical prediction.
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Kouichi Ishiyama, Keizo Endo, Toshiro Sakakibara, Tsuneaki Goto, Kiyoh ...
1987 年 56 巻 1 号 p.
29-31
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Anomalous magnetization curves observed under the strong pulsed magnetic fields up to 520 kOe are understood with itinerant electron metamagnetism. From the results of Sc(Co
1−xAl
x)
2 the critical field of the transition and the spontaneous moment after the transition of ScCo
2 can be estimated to be a few megagauss and about 0.4 μ
B/Co, respectively. These are consistent with recent theoretical results.
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Masafumi Yamashita, Makio Kurisu, Hideoki Kadomatsu, Isamu Oguro, Hiro ...
1987 年 56 巻 1 号 p.
32-35
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
The electrical resistivity and the magnetization of CeZn
2 have been measured. Kondo anomaly is found in the electrical resistivity and the magnetization shows a very large magnetic anisotropy and metamagnetic transitions with three steps only for fields along
b-axis. The saturation magnetization per Ce is 1.75 μ
B at 1.3 K and 4.2 K. These results are briefly discussed with a recent theory of Kondo effect and a simple thermodynamical model.
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Yoshiei Todate, Kazuyoshi Yamada, Yasuo Endoh, Yoshikazu Ishikawa
1987 年 56 巻 1 号 p.
36-38
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Spin-waves in MnP have been measured by means of neutron inelastic scattering at various temperatures. Dispersion relation along
a-axis exhibits anomalous wave vector and temperature dependences, while the quadratic
q dependence was observed along both
b and
c-axis. The characteristic feature of the spin-wave dispersion relations agree qualitatively with those predicted on analogy with rare earth metals.
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Makoto Kuwata, Nobukata Nagasawa
1987 年 56 巻 1 号 p.
39-42
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Photo-induced depolarization effect of linearly polarized beam in the giant two-photon absorption (GTA) band of excitonic molecules was examined in CuCl with the use of non-linear ellipsometry. After the careful elimination of the instrumental optical anisotropy, no depolarization was observed under the excitation of 1 MW/cm
2. The stability of the linearly polarized state was also studied by measuring the polarization character for a slightly elliptical beam and a partially polarized beam. Growth of the depolarization was found in both cases and thus the linear polarization is concluded to be an unstable state in the GTA resonance.
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Mikio Shimizu
1987 年 56 巻 1 号 p.
43-45
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Specific interactions of anticodonic dinucleoside monophosphates and their cognate amino acids have been detected by using a precise ultraviolet difference asbsorbance photometry. The affinity coefficients are of the order of 1 M
−1, similar to those in the base-base stacking interactions, suggesting the lock and key relationship for the above interaction. All signals are hyperchromic and may be caused by destacking of the dinucleoside monophosphate due to the above complex formation.
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Kazuaki Narita
1987 年 56 巻 1 号 p.
47-51
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
One and four types of asymmetric discrete envelope soliton solutions are found for semi-discrete sine-Gordon equation and semi-discrete wave equation with cubic nonlinearity. They are found by appropriately transforming the variables of already-known discrete envelope soliton solutions. Some properties of these solutions are discussed.
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S. V. Godoy, Shigeji Fujita
1987 年 56 巻 1 号 p.
52-59
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The arrival probabilities with directions for a linear biased correlated walk, satisfy coupled linear difference equations. An exact analytic solution to these equations with a periodic boundary and a general initial condition, is obtained. The solution for an inhomogeneous initial condition can be expressed in terms of the Chevyshev polynomials of the second kind, and is quite complicated. For a homogeneous initial condition, the analytic expressions for the arrival probabilities can be written down in single lines. With a finite bias, the system approaches a stationary state in which the ar-rival probabilities are different for different directions, and a finite current exists. As an application of the theory, a dilute solution of CO in liquid Ar under an electric field is discussed.
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Willem Overlaet, Masahiro Kimura, Shuichi Kinoshita, Takashi Kushida
1987 年 56 巻 1 号 p.
60-69
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Time characteristics of the secondary emission from iodine molecules excited with light pulses from a cavity-dumped, single-frequency Ar
+ ion laser at 514.5 nm have been compared with existing theories. It has been found that the experimental data are well explained quantitatively by the theories, provided the 21 hyperfine lines as well as collisional effects and Doppler broadening are taken into account. The cross sections for the phase-changing and population-changing collisions have also been determined. The contributions of coherent and incoherent secondary emission processes are discussed.
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Hiroyuki Nishimura, Toshiyuki Matsuda, Atsunori Danjo
1987 年 56 巻 1 号 p.
70-78
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
The differential cross section (DCS) for elastic electron scattering from Xe has been measured using a crossed beam method. The measurements were carried out in the angular range from 10° to 125° and at incident energies from 5 eV to 200 eV. The absolute values of the DCS have been determined by means of the relative flow method. The integral and momentum-transfer cross sections are derived from the measured DCS. The results are compared with those of previous experimental and theoretical studies.
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Fujihiro Hamba
1987 年 56 巻 1 号 p.
79-96
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Diffusion and reaction of chemically reacting passive scalars in turbulent shear flows are investigated. A binary irreversible reaction with no heat release is considered. The binary and triple correlations such as the scalar fIux, the scalar variance, and the squared-scalar flux are calculated by applying a two-scale direct-interaction formalism. The results are simplified by the use of the inertial-range theory to construct two models for the passive scalars: an ensemble-averaged model of
k-ε type, and a LES model.
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M. A. Hossain, R. I. M. A. Rashid
1987 年 56 巻 1 号 p.
97-104
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Effect of Hall current on the unsteady free convection flow of a viscous incompressible and electrically conducting fluid, in presence of foreign gases (such as H
2, CO
2, H
2O, NH
3), along an infinite vertical porous flat plate subjected to a transpiration velocity inversely proportional to the square-root of time is investigated in the presence of a uniform transverse magnetic field. The results are discussed with the effects of the parameters Gc (the Grashof number for mass transfer), m (the Hall parameter) and Sc (the Schmidt number) for Pr=0.71, which represents air.
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S. Acharyya, I. L. Saha, A. K. Datta, A. K. Chatterjee
1987 年 56 巻 1 号 p.
105-114
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The variation of column calibration factor
Fs with respect to temperature change has been attained for a given column (C.J.G. Slieker and A. E. de Vries: J. Chim. Phys.
60 (1963) 172) to estimate the temperature dependence of thermal diffusion factor α
T of trace mixtures of hydrogenic isotopes in helium only to detect the existence of inelastic collision effect in the mixtures as predicted by T. K. Chattopadhyay and S. Acharyya (J. Phys. B
7 (1974) 2277). Attempts have also been made to interpret the α
T’s thus obtained in terms of the available elastic and inelastic collision theories of thermal diffusion to establish the importance of the column calibration factor in column measurements.
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Nobuaki Ikuta, Yukio Murakami
1987 年 56 巻 1 号 p.
115-127
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
A method to evaluate the transport coefficients of charged particles under an electric field is developed. Two velocity-distribution functions
Ψs(
v0) and
Ψc(
v′) are introduced in addition to the usual velocity-distribution function
f(
v). Here,
Ψs(
v0)d
v0 and
Ψc(
v′)d
v are the probabilities of a charged particle starting a new flight with a velocity in the range
v0, d
v0, and making a collision at a velocity in the range
v′, d
v′, respectively. The velocity-dispersion functions through flight,
H(
v′,
v0), and through scattering,
S(
v0′,
v′) are used to determine
Ψs(
v0). Since
H(
v′,
v0) includes the full information on the flight of charged particles, the transport coefficients defined in real space have to be expressed directly by
Ψs(
v0). The velocity-distribution function
f(
v) and the transport coefficients defined in velocity space are also expressed by
Ψs(
v0). This method is simple but is applicable to anisotropic systems.
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Jiro Todoroki
1987 年 56 巻 1 号 p.
128-138
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Formulae of stellarator approximation valid for finite aspect ratio helical tori are derived by using coordinate transformation and method of averaging. The three dimensional problem of MHD equilibrium and stability is reduced to two dimensional one; this makes possible to convert tokamak codes to stellarator codes. Importance of including residual magnetic field to recover the three dimensional magnetic field from averaged equilibrium is pointed out.
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S. Sutradhar, S. Bujarbarua
1987 年 56 巻 1 号 p.
139-143
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Ion acoustic double layer solutions have been obtained in a plasma in presence of a negative species of ions. It has been shown that the rarefactive double layer solutions exist when the negative ion concentration is less than a limiting value. our theoretical result is in good agreement with the recent observation of rarefactive double layers moving from the ionosphere to the magnetosphpere of the earth.
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Osamu Naito, Kenro Miyamoto
1987 年 56 巻 1 号 p.
144-149
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Analysis of θ pumping for tokamak current drive is presented. Diffusion of an externally applied oscillating electric field into a tokamak plasma is examined. When the oscillating electric field is in the same direction as the stationary toroidal plasma current and the current density induced by the applied electric field is larger than the average density of the plasma current over the plasma cross section, the radial profile of the safety factor has an extremum near the plasma boundary region and MHD instabilities are excited. It is assumed that anomalous diffusion of the current induced in the plasma boundary region takes place, so that the extremum in the radial profile of the safety factor disappears. The anomalous electric field due to this relaxation process has a net d.c. component, which is estimated, and the condition for tokamak current drive by θ pumping is derived. Some numerical results are presented for the case of a fusion grade plasma.
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Keiji Matsuo, Hiromi Nitta, Yoshito Sonoda, Katsunori Muraoka, Masanor ...
1987 年 56 巻 1 号 p.
150-157
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The low-frequency electron-density fluctuations in the mirror-cusp device RFC-XX-M were measured using the Fraunhofer-diffraction method. The density fluctuations by the microinstability were identified to be of the drift-wave mode, by the discussions of the dispersion relation, range of the wave-numbers (
k⊥ρ
i\simeq1, where
k⊥ is the wave-number in the plane perpendicular to a magnetic field and ρ
i is the ion Larmor radius), the localization at the density gradient, and the growth rate. Further, effects of the fluctuations on mirror confinement were discussed and the particle confinement time was deduced from the measured fluctuation intensity.
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Hirofumi Fukumoto, Keiji Tsunetomo, Takeshi Imura, Yukio Osaka
1987 年 56 巻 1 号 p.
158-162
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Amorphous GeTe
2 films with the thickness ∼0.5 μm, prepared by sputtering technique, transform into the crystalline GeTe
2 films with the isomorphic structure to β-cristobalite, cubic SiO
2, at
Ta(annealing temperature)=200°C. The cubic phase of GeTe
2 is metastable and decomposes into the mixed crystal of GeTe and Te at
Ta=250°C.
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Izumi Tomeno, Sadao Matsumura
1987 年 56 巻 1 号 p.
163-177
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Elastic constants
C11,
C33,
C44, and
C66, and dielectric susceptibilities χ
11 and χ
33 in LiNbO
3, were determined over the temperature range from 300 to above 1030 K. The elastic-constant difference between constant polarization and constant field
CiiP−
CiiE, and the inverse-susceptibility difference between constant strain and constant stress (χ
iix)
−1−(χ
iiX)
−1 are interpreted in terms of both electrostrictive and higher-order interaction between strain and polarization. The results for χ
33 indicate that LiNbO
3 undergoes nearly second-order phase transition at
TC=1410 K. Above
TC, χ
33 showed dispersion in the frequency range between 1 and 13 MHz. A comparison of these results with soft-mode frequency implies that the soft mode couples with a low frequency relaxation process near
TC.
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Yukio Saito, Kazushi Furuta, Masato Hojou
1987 年 56 巻 1 号 p.
178-194
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Phase transitions of the triangular Ising model in a field with nearest and second nearest neighbor antiferromagnetic interactions with couplings, −
J and −
J⁄2, respectively, are studied by the interfacial free energy method, by the mean field approximation, by the transfer matrix and phenomenological renormalization methods and by the Monte Carlo simulation. At low temperatures and at fields weaker than the lower critical field
hc1 the system takes the 2×1 structure, and at fields between
hc1 and the upper critical field
hc2 it takes the 2×2 structure. Between the 2×1 and 2×2 phases near the field
hc1, a partial disordered phase, in which a part of the sublattices are in disorder, is found. Specific heat shows no divergence, when the partial disordered phase changes to other phases.
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Yoshihiro Ishibashi
1987 年 56 巻 1 号 p.
195-199
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Electric-field induced phase diagrams are discussed for the group of crystals like NaNO
2 and SC(NH
2)
2 having incommensurate phases, on the basis of a relevant Landau-type thermodynamic potential. Several different phase diagrams derived from it are presented.
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Eiko Matsushita, Takeo Matsubara
1987 年 56 巻 1 号 p.
200-207
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
From a microscopic viewpoint on the role of two kinds of hydrogen bonds, antiferroelectric phase transition in NH
4H
2PO
4 is re-examined. The role played by the protons of NH
4 ions is explicitely taken into account, and it is shown that the hydrogen bonding effect of NH
4 ions with neighbouring oxygens may be renormalized into the effective antiferroelectric interaction between protons which form the network of hydrogen bonds connecting PO
4 groups.
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Kiyoshi Deguchi, Yasuyuki Okada, Hideki Fukunaga, Eiji Nakamura
1987 年 56 巻 1 号 p.
208-216
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
The commensurate (C)-incommensurate (IC) phase transition in Rb
2ZnCl
4 has been investigated through studies of the X-ray diffraction and the
P-
E hysteresis loop. Simultaneous observation of the
P-
E hysteresis loop and the misfit parameter reveals that the double hysteresis loop observed in the IC phase corresponds to the field induced C–IC transition. The “triple”-like hysteresis loop observed in the vicinity of the C–IC phase transition temperature corresponds to the coexistence of the IC and the C state near
E=0 followed by the field induced C–IC transition at a finite value of
E. The effect of pinning on the electric field dependence of the misfit parameter and the polarization is considered on the basis of the Landau type theory. The tendency of the calculated results agrees well with that of the experimental results.
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Hisashi Hiramoto, Kenji Nakao
1987 年 56 巻 1 号 p.
217-224
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
By using the molecular dynamics method, structural and dynamical properties of a model system of C
8K type compounds are studied. The model consists of one intercalant layer sandwiched by rigid graphite layers. The solid-liquid transition of intercalant ion system is observed, and the static and dynamical properties of the liquid state are investigated. The calculation of the pair distribution function clarifies the characteristic local structure of the “liquid”. The observation of traces of the ionic motions reveals that the motions of ions have a strong correlation. It is not the case that an individual ion jumps from a site to another one independently. The analysis of the activation energy of the calculated self-diffusion constant of the intercalant ions also leads to a conclusion consistent with this.
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Hideoki Hoshino, Hirohisa Endo
1987 年 56 巻 1 号 p.
225-232
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
The mass density of liquid Se–Te mixtures up to 20 at.% Te was measured by the Archimedean method in the temperature and pressure ranges up to 1350°C and 1200 bar. It was observed that at 20 at.% Te the isochore curves show maxima on the
P-
T plane. The thermal expansion coefficient α
P derived from the isochore curve data changes sign from positive to negative around 19 at.% Te at 1000°C and 100 bar. The concentration where α
P changes sign moves to Se-rich side by application of pressure. The anomalous behaviour in the isochore curve suggests the occurrence of the structural transition.
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Shunsuke Hirotsu
1987 年 56 巻 1 号 p.
233-242
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
A volume phase transition of poly-N-isopropylacrylamide (NIPA) gel immersed in some pure and mixed solvents has been investigated experimentally. A slightly discontinuous transition of NIPA get in water changed to a more distinctly first-order transition on adding a small amount (<20%) of alcohols to water. As the concentration of alcohols in the mixed solvent increased further, the volume transition blurred and eventually disappeared. Analyzing the experimental results on the basis of the mean field theory of polymer solution, it has been shown that the polymer-solvent interaction parameter χ exhibits a drastic change at the volume transitions. This indicates that the enthalpy and entropy of solution depend strongly on polymer concentration.
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Shinji Hayashi, Hiroyuki Wakayama, Tadashi Okada, Soon Sik Kim, Keiich ...
1987 年 56 巻 1 号 p.
243-249
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Effects of thermal annealing on gas-evaporated Ge microcrystals as small as 90 Å were investigated by Raman spectroscopy and electron microscopy. It is found that the size of microcrystals abruptly increases when they are annealed at 500°C, presumably due to the surface melting coalescence. The abrupt growth of microcrystals leads to an abrupt increase in the intensity of crystalline Raman signal. The close similarity between the spectral changes presently observed and those previously observed for a-Si and a-Ge films suggests that the crystallization process in so-called amorphous films can be well understood in terms of the growth of microcrystals.
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Yositaka Onodera
1987 年 56 巻 1 号 p.
250-254
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The quasi-one-dimensional chains of halogen-bridged mixed-valence platinum complexes (HMPC) have characteristic twofold degeneracy similar to the trans isomer of polyacetylene, which strongly suggests the presence of soliton-like excitations in HMPC. It is shown that the microscopic Hamiltonian proposed by Ichinose for HMPC, which naturally is different from the Su-Schrieffer-Heeger model of
trans-polyacetylene, leads to the Takayama-Lin-Liu-Maki Hamiltonian when the continuum limit is taken. This theoretical result implies that we can expect various soliton processes found in
trans-polyacetylene to take place in HMPC as well, though such experimental evidences are scarce as yet.
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Hidenori Abe, Teruhiko Mabuchi
1987 年 56 巻 1 号 p.
255-264
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The Madelung energies and the first and second derivatives of the crystal potentials at two unequivalent NH
4+ ion sites and one SO
42− ion site in (NH
4)
2SO
4 crystals have been calculated by the point charge model at various temperatures from 25 to −140°C. The Ewald’s method improved by Honma has been used for lattice sums. This new method has been less influenced by the choice of a type of a unit cell and has given more rapid convergence than the method in which summations are taken only over real space. The temperature dependence of the optical absorption spectra of (NH
4)
2SO
4: Tl is analyzed by using the crystal fields of the host crystal, and fairly good agreements with the experiment are obtained.
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Hidenori Abe, Teruhiko Mabuchi
1987 年 56 巻 1 号 p.
265-275
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
One electron molecular orbital(MO) energy levels of Tl-(SO
4)
n complexes in (NH
4)
2SO
4 have been calculated by using the charge-consistent extended Hückel method at various temperatures from 25 to −140°C. The calculation has been performed both for the ground and excited states, and the result shows that the highest occupied MO in the ground state,
s′, mainly consists of the thallous 6
s orbital, and the lowest three partially occupied MO’s in the excited state,
p1,2,3′
*, consist of the thallous 6
p orbitals. The optical absorption bands of (NH
4)
2SO
4:Tl are attributed to the transitions between MO’s,
s′ and
p1,2,3′
*. The temperature dependence of the absorption spectra is explained by that of both the energies of MO’s and the crystal fields of (NH
4)
2SO
4 crystals.
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Hidenori Abe, Teruhiko Mabuchi
1987 年 56 巻 1 号 p.
276-282
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The absorption spectra of ammonium sulphate, (NH
4)
2SO
4, crystals containing a small amount of thallous ions have been measured in the energy region from 20000 to 60000 cm
−1. At 15°C only one broad band is found for all of
a,
b and
c-polarized lights below the fundamental absorption edge of the host crystals. However, at −196°C the band for
c-polarized light is split into two, 46450 and 47750 cm
−1, and for
a-polarized light there appears a shoulder in the higher energy side of the band. These absorption bands are attributed to the superposition of the transitions between the molecular orbitals in the two unequivalent Tl-(SO
4)
n complexes. The temperature dependence of the absorption spectra is explained by that of the molecular orbital energies of the complexes and that of the crystal fields of (NH
4)
2SO
4 crystals.
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Satoru Ohno, Fujio Kakinuma
1987 年 56 巻 1 号 p.
283-290
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The increase in the conductivity,
Δσ, and the increase in the paramagnetic susceptibility,
Δχ
p, by the addition of noble metal solutes were experimentally studied in liquid Se–Te mixtures. The curve of
Δσ versus the square root of the conductivity of solvent σ
1⁄2 has a broad maximum in the intermediate region where metal-nonmetal transitions gradually occur in liquid Se–Te mixtures. The trend of
Δχ
p versus σ
1⁄2 has also a broad maximum in the relatively low conductivity region. The broad maxima of
Δσ and
Δχ
p are suggested to be closely related to the formation of the delocalized threefold site and the dangling bond state which are induced by the addition of noble metal solutes.
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Takamitsu Kobayashi, Shigeki Kojima, Mieko Ohtsuka
1987 年 56 巻 1 号 p.
291-294
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Irreversible resistivities of as-deposited indium films during annealing process were measured. Using Vand’s theory, an activation energy of defect,
E, and the initial lattice distortion energy function,
F0(
E), were evaluated. The spectrum of
F0(
E) showed two peaks, one at the activation energy
Emax1=0.30 eV, and the other at
Emax2=0.45 eV. The dependence of the activation energies on the film thickness were not observed. But the values of
F0(
Emax1) and
F0(
Emax2) were dependent on the film thickness. It is suggested that the peak at
Emax2 is related to the stress introduced during the annealing process.
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Hideo Nakajima, Yoshihisa Obi, Yuji Fukumoto, Hiroyasu Fujimori
1987 年 56 巻 1 号 p.
295-300
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Multilayered Nb/Ti thin films were made by a dual dc- and rf-sputtering technique. The samples with modulation wavelength λ ranging from 2000 Å down to 20 Å were prepared. X-ray diffractometry shows that the as-deposited multilayer modulation is sinusoidal in the shorter wavelength, while nearly square in the longer wavelength. Irrespective of the wavelength λ, the Nb is bcc with stacking of (110) parallel to the substrate, and the Ti is either the stacking of hcp(00.2) or bcc(110). The superconducting transition temperature
Tc is close to that for bulk Nb (9.3 K) in the region λ>1000 Å, while
Tc decreases to 4 K with decreasing λ in the region 50<λ<1000 Å. Dependence of the transition temperature on the wavelength is in good agreement with that observed by Qian
et al. and is explained by the proximity effect according to Werthamer theory.
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Yutaka Nakai, Masahumi Sakuma, Nobuhiko Kunitomi
1987 年 56 巻 1 号 p.
301-310
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The magnetic phase diagram of an fcc alloy AuCr has been constructed by means of magnetic and neutron diffraction measurements. It shows a nature of spin glass at dilute concentration of Cr and a nature of a long range antiferromagnetism at high concentration. At intermediate concentration, about 11 to 13 at.% Cr, it has short range antiferromagnetic clusters. Since the cluster size is almost independent of temperature change below the freezing temperature of spins which is determined by the susceptibility measurement, we can conclude that the intermediate phase is composed of antiferromagnetic clusters frozen in the matrix of spin glass. Near 13 at.%Cr, the system has narrow region which shows the reentrant property.
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Masatoshi Imada
1987 年 56 巻 1 号 p.
311-335
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Finite size calculation up to 18 spins combined with the extrapolation to the thermodynamic limit is performed to obtain thermodynamic properties of spin 1/2 triangular antiferromagnet. It shows that both of isotropic and Ising-like Heisenberg systems are in quantum spin fluid state at low temperatures with the singlet ground state. In contrast with the classical system, the result is consistent with the picture that the sublattice ordering has no relevance and no phase transition occurs.
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Takayoshi Takeda, Tsutomu Watanabe, Shigehiro Komura
1987 年 56 巻 1 号 p.
336-339
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Mössbauer effect measurements of
57Fe in SrFe
1−xCo
xO
3(0≤
x≤0.5) have been performed at room temperature, 77, 64 and 4.2 K in order to study the electronic structure of Fe
4+ ions. The Mössbauer spectra at 4.2 K were a single set of magnetically split lines, the form of which varied little with
x. It is confirmed by the present study that Fe
4+ ions have nearly a high spin electron configuration for 0≤
x≤1. Mössbauer spectra at 77 K had a paramagnetic line as well as magnetically split lines in the range of 0.05≤
x≤0.15, in which local fluctuation of composition of Co is considered to give rise to a magnetically inhomogeneous structure.
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Hitoshi Yamazaki, Mamoru Chikamatsu, Motoyuki Tanaka
1987 年 56 巻 1 号 p.
340-346
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
By parallel pumping experiments antiferromagnetic spin-wave frequencies at the Brillouin-zone-boundary in (C
2H
5NH
3)
2CuCl
4 have been measured as a function of static magnetic fields below the spin-flop critical field. The experimental results are in good agreement with the spin-wave theory which includes the effect of the magnetic dipolar interaction. Measurements have been done at pumping frequencies from 7.7 to 10.8 GHz and in the temperature range from 1.4 to 2.6 K. The instability threshold of the zone-boundary magnons is empirically described as
H1c=0.30×
T2.46 Oe.
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Kiyoyasu Imai, Hiroaki Ishida
1987 年 56 巻 1 号 p.
347-351
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
The electrostrictive corrections have been made to a previous theory based on the pseudo one-dimensional Ishing model. The corrected results explain well the dielectric and the heat-capacity data of CsD
2PO
4 (d-CDP) both in the para- and ferroelectric phases even without the proton-tunnelling terms, but they are not so successful in the case of CsH
2PO
4 (CDP). The ratio of the effective dipole moments which indicates the strength of the effect of proton-tunnelling [Levstik
et al.: J. Phys. C
19 (1986) L25] is evaluated as μ
ε⁄μ
p=1.2 for CDP. This value suggests that, in CDP, the tunnelling-effect cannot be neglected.
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Nobuhiko Yamashita, Sumitada Asano
1987 年 56 巻 1 号 p.
352-358
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Details of emission and excitation spectra of powder phosphors were obtained at various temperatures between 6 K and room temperature. The emission spectra consist of six groups of emission lines located at about 565, 605, 650, 710, 790 and 900 nm at 300 K. The position of each emission line shifts slightly towards shorter wavelengths in the order, MgS:Sm
3+, CaS:Sm
3+, SrS:Sm
3+ and BaS:Sm
3+. The first five groups are assigned to the transitions from the
4G5⁄2 state to the
6HJ(
J=5⁄2, 7/2, 9/2, 11/2, 13/2) states and the last group to the
6FJ(
J=1⁄2, 3/2, 5/2) states in a Sm
3+ ion. The excitation processes are explained as being due to three transitions; (i) the transitions within the 4
f5 configuration in a Sm
3+ ion, (ii) the electronic 4
f5→4
f4·5
d transition in a Sm
3+ ion and (iii) the fundamental absorption in host crystal, followed by the transfer of the excitation energy to an unexcited Sm
3+ ion.
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Shin-ichi Nakashima, Yasuhiro Nakakura, Zenzaburo Inoue
1987 年 56 巻 1 号 p.
359-364
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Raman scattering spectra of SiC polytypes 27R and 33R have been measured with a back scattering geometry using a (0001) face. The relative Raman intensities of folded modes in transverse acoustic (TA) and transverse optic (TO) branches have been calculated with the aid of a linear chain model. The calculated Raman profile for each branch agrees semi-quantitatively with the observed spectrum. The result indicates that the Raman intensity analysis of the folded modes can be used to identify the polytype of SiC with longer period.
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Hirokazu Sakamoto, Hirofumi Namatame, Tamiko Mori, Koichi Kitazawa, Sh ...
1987 年 56 巻 1 号 p.
365-369
発行日: 1987/01/15
公開日: 2007/05/29
ジャーナル
認証あり
Photoemission spectra of BaPb
1−xBi
xO
3 are measured for
x=0, 0.25, 0.3 and 0.6 by use of synchrotron radiation. A remarkable discrepancy from the results of band calculation is recognized. It is found that the O 2p
⊥ band has a high density of states (DOS) at binding energies (
EB) of 3.0∼3.5 eV. The DOS at the Fermi level (
EF) is found to be negligibly small in all samples. The
EB of the Pb 5d bands for
x=0.3 and 0.6 are around 0.3 eV smaller than those for
x=0. It is also found that the Ba 5p core levels shift to larger
EB by ∼0.3 eV with increasing
x. The Bi 5d core levels have shown no additional structure besides the spin-orbit splitting, whereas the Pb 5d core spectra are remarkably distorted for
x=0.3 and 0.6. These effects are discussed in regard to the charge transfer and the hybridization of electronic states.
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Goro Mizutani, Nobukata Nagasawa
1987 年 56 巻 1 号 p.
370-377
発行日: 1987/01/15
公開日: 2007/06/01
ジャーナル
認証あり
Photo-induced reflectivity change in
Z3-exciton region of a CuCl single crystal ∼3.4 μm thick has been studied to monitor the inhomogeneous distribution of high density excitons. A pump and probe technique has been used. The results have been analyzed qualitatively using a model in which the reflection of light from a dielectric composed of a directly photo-modulated thin layer and a moderately modulated remaining region is treated. In a typical case of ∼5 MW/cm
2 excitation at 3.234 eV at 1.6K, the shift of the
Z3-exciton energy and its damping constant in the directly modulated layer have been estimated to be 3±1 meV and 4±1 meV, respectively. The effective thickness of the layer has been evaluated to be less than 0.2 μm. A fact suggesting the propagation of photo-excitation effects toward the rear surface region which is far apart compared with the penetration depth of the pump beam has been found.
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