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Yujiro Ikeda, Hiroshi Yamamoto, Kiyoshi Kawade, Tokuo Takeuchi, Toshio ...
1979 Volume 47 Issue 4 Pages
1039-1046
Published: October 15, 1979
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The decay of
148Pr to levels on
148Nd has been investigated with Ge(Li) and plastic detectors in singles and coincidence modes. Sources were prepared by a chemical separation from the fission products of
235U. Forty γ-rays associated with
148Pr decay have been observed and thirty four of them are incorporated into a level scheme including six new levels at 723.7, 1275.0, 1512.4, 1687.5, 2543.0 and 3129.6 keV. In comparison with the decay study of
148Pr produced by the
148Nd(n, p) reaction, this work, for the first time, could make clear the existence of
148Pr isomers by γ-ray intensity ratios and their half-lives which are 2.27±0.04 and 2.0±0.1 min. A low lying level at 723.7 keV is assigned as a 0
+ state from the γ-γ anisotropy measurements and low lying levels in the transitional nuclide
148Nd are discussed in terms of the quasi band description.
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Mamoru Uchinami, Satoshi Takada, Fumihiko Takano
1979 Volume 47 Issue 4 Pages
1047-1053
Published: October 15, 1979
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The spin wave theory of Kondo and Yamaji is applied to the spin 1/2 XY model in one to three dimensions. In one dimension, the value of the gap
Δ which appears in the spectrum of
x-component spin remains finite up to 0 K, and no phase transition occurs. The value of the nearest neighbour correlation function is in good agreement with the exact values. In three dimensions,
Δ vanishes at a finite temperature, and the second order phase transition occurs. In two dimensions, as
T→0,
Δ becomes very small for square lattice and tends to zero as exp (−
T0⁄
T) for triangular lattice, which means the non-existence of the phase transition. The susceptibility, however, becomes anomalously large for low temperatures, and the extrapolation of Curie-Weiss law gives a “fictitious” transition temperature whose value agrees with those given by the high temperature expansion and the real space renormalization group theory.
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Kichizo Asai, Hisashi Sekizawa, Shuichi Iida
1979 Volume 47 Issue 4 Pages
1054-1060
Published: October 15, 1979
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Magnetization measurements and
55Mn NMR study of a system with the nominal formula LaNi
1−xMn
xO
3 (0.0≤
x≤0.5) were made. It was found that materials with 0.03≤
x≤0.5 are mixtures of a Pauli paramagnet LaNiO
3 and a ferromagnet LaNi
0.5Mn
0.5O
3. The Curie temperature of LaNi
0.5Mn
0.5O
3 was found to be 275 K. In this material, strong
55Mn NMR signals associated with Mn
4+ were observed. The observed hyperfine magnetic fields are about −260 kOe, which is considerably smaller than the ones observed for the Mn
4+ ions in other oxides. This smallness of the value seems to be due to the supertransferred hyperfine magnetic fields from the neighboring Ni
2+ ions.
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Nobuo Wada, Koh Matsumoto, Kiichi Amaya, Taiichiro Haseda
1979 Volume 47 Issue 4 Pages
1061-1068
Published: October 15, 1979
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Susceptibility χ and specific heat
Cp of the single crystal of Ni(NO
3)
2·6H
2O are measured from 0.6 K to 0.06 K around 45 kOe. The field direction is adjusted to the
z-axis of the crystal field of Ni
2+ ions in an accuracy of 0.5°. On the
T-
H phase diagram thus obtained, the critical fields at 0 K are 38 kOe and 48 kOe. Two maxima of critical temperature
Tc, 93 mK at 41.4 kOe and 89 mK at 45.2 kOe, are found on the phase boundary. An unexpected minimum of
Tc is observed at 81 mK at 43.4 kOe. A maximum of Schottky type in
Cp and χ is observed at higher temperature region outside the phase boundary. These behaviors are well explained by the model of an Ni
2+ spin-pair coupled by an antiferromagnetic interaction. The intra-pair interaction is estimated to be 2
J⁄
k=0.25 K, and two kinds of inter-pair interaction are 2|β|⁄
k=2|
J11−
J12|⁄
k=0.14 K and 2α⁄
k=2(
J11+
J12)⁄
k=0.40 K.
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Kaoru Yamafuji, Teruo Matsushita
1979 Volume 47 Issue 4 Pages
1069-1077
Published: October 15, 1979
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A macroscopic theory is presented for the semi-quasistatic flux distribution in a nonideal type II superconductor in the presence of a transport current under a longitudinal magnetic field. The present theory is based on a new concept of the irreversible force-free current which originates from the shearing deformation of flux-line lattice due to the interactions with pins. By the use of the resultant pinning-current-density tensor, the flux distribution is calculated for a slab sample, and the results provide a reasonable explanation for observed data. It is also pointed out that the transition to the resistive state may occur when the rotationally shearing deformation of the flux-line lattice reaches the center of the sample.
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Hideoki Kadomatsu, Fumiaki Ishii, Hiroshi Fujiwara
1979 Volume 47 Issue 4 Pages
1078-1085
Published: October 15, 1979
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Measurements of the magnetization, lattice constants and hydrostatic pressure effect on the Curie temperature
Tc were carried out on the compounds (Co
1−xMn
x)
2B, 0≤
x≤1. The compounds were ferromagnetic when
x\lesssim0.6 and paramagnetic when 0.6\lesssim
x≤1. The magnetization at 4.2 K and
Tc were analysed on the basis of the pair interaction model and the local environment effect, on the assumption that the central Co atom loses the moment or the moment of Mn is antiparallel to the neighboring Mn atoms, when the numbers of neighbor Mn atoms are more than seven. The composition dependence of lattice constants
a and
c did not follow the Vegard’s law, and was explained by the magnetic contribution. The data on the pressure effect on
Tc shows relatively large contribution of the Mn–Mn pair to the exchange interaction.
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Shunichi Kawanishi, Akira Tasaki, Kiiti Siratori
1979 Volume 47 Issue 4 Pages
1086-1090
Published: October 15, 1979
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A giant cubic anisotropy was observed in the magnetic torque measurement of ZnCr
2Se
4 single crystals above
TN, doped with Mn in the order of 1%. No such anisotropy was found in pure ZnCr
2Se
4. Shape and magnitude of the anisotropy could not be interpreted by the fine structure of isolated Mn
2+ ions. Cr
3+ spin clusters around Mn impurities seem to be the origin of the anisotropy, though the mechanism is not clear.
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Kôji Ueno, Kunisuke Asayama
1979 Volume 47 Issue 4 Pages
1091-1093
Published: October 15, 1979
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The distribution of the internal field at
55Mn in (
Ni1−xRhx)Mn and (
Ni1−xRux)Mn has been investigated. In Rh alloy the NMR signals due to Mn atoms with parallel and antiparallel moment to the host are observed. The critical number to reverse the moment is estimated to be about 5.
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Kôji Ueno, Kunisuke Asayama
1979 Volume 47 Issue 4 Pages
1094-1101
Published: October 15, 1979
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The nuclear transverse relaxation time,
T2 of
55Mn were measured in ferromagnetic (
Ni1−xRhx)Mn, (
Ni1−xFex)Mn and Ni
1−xMn
x alloys.
T2 is governed by
T1 and depends strongly on transition temperature and resonance frequency. An extended expression of the Weger mechanism, the relaxation mechanism due to the interaction of nuclear spin with the conduction
s electrons via the spin wave is derived for the impurity relaxation rate in a dilute ferromagnetic alloys, and is applied to explain the relaxation behavior in the present experiment. The dependence of
T2 on the local environment is concluded to be due mainly to the variation of the effective exchange coupling between a Mn moment and its neighbors.
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Fumitaka Matsubara, Sakari Inawashiro
1979 Volume 47 Issue 4 Pages
1102-1109
Published: October 15, 1979
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The magnetic properties and the phase diagram of the solid solution Co
xNi
1−xCl
26H
2O are analyzed by using a model Hamiltonian with the mean field approximation. Our results are qualitatively in agreement with experimental ones. It is shown that the sublattice magnetization lies in a plane including both easy axes of two pure substances (
ca-plane) and its direction varies smoothly over the whole range of the concentration
x, not within a limited range of
x as observed in K
2Mn
xFe
1−xF
4 and Co
xFe
1−xCl
22H
2O. The feature is due to off diagonal terms in the Hamiltonian which come from the non-orthogonality of the easy axes of two pure substances CoCl
26H
2O and NiCl
26H
2O (∼65°). The characteristic features of the magnetization processes are also analyzed considering the fact that the second easy axis of CoCl
26H
2O does not lie within the
ca-plane.
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Migaku Takahashi, Shizuo Kadowaki, Tokuo Wakiyama, Takeshi Anayama, Mi ...
1979 Volume 47 Issue 4 Pages
1110-1116
Published: October 15, 1979
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The uniaxial magnetic anisotropies,
Kuf, induced by magnetic annealing and
Kur by cold rolling were investigated for Co and Co–Ni alloys containing Ni up to 30%. The values of
Kuf obtained for Co–Ni alloys ranged from −4 to 8×10
5 erg/cm
3 in fairly good agreement with the earlier results. The obtained values of
Kur are about −2×10
5 erg/cm
3 for any composition of alloys. The pole figure analysis by the Schulz’s reflection method with X-ray was carried out. The results revealed no texture for the magnetically annealed specimens. Contrary, for the cold rolled specimens, the crystallographic texture was detected, even though the magnitude of
Kur is smaller than that of
Kuf. Influence of annealing on
Kuf and
Kur was examined in the range of temperature between 300 and 1000°C. By the annealing above the phase transformation temperature the value of
Kur is reduced suddenly, while the value of
Kuf remains unchanged.
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Migaku Takahashi, Shizuo Kadowaki, Tokuo Wakiyama, Takeshi Anayama, Mi ...
1979 Volume 47 Issue 4 Pages
1117-1124
Published: October 15, 1979
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A statistical model developed by Trout and Graham is used to describe the induced magnetic anisotropies,
Kuf, by magnetic annealing and
Kur by cold rolling, taking into account the orientation of the easy axes of magnetization and the slip system for h.c.p. crystal. In the case of cold rolling, the calculated absolute value of
Kur is nearly the same as the experimental one, however the sign of them disagrees each other. In the case of magnetic annealing, since the crystallographic texture is not present, it is attempted to estimate the volume fraction of the grains having preferred orientation to the whole volume of the specimen. The estimated volume fraction is more than 20% and is enough to detect the crystal-lographic texture within the accuracy of the X-ray measurement carried out in a preceding paper. It is concluded that the origin of the magnetic annealing effect for Co and Co–Ni alloys is not attributed to the formation of crystallographic texture.
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Takahisa Ohno, Kenji Nakao, Hiroshi Kamimura
1979 Volume 47 Issue 4 Pages
1125-1133
Published: October 15, 1979
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The method of the band structure calculation for layer-type materials is presented with use of atomic pseudopotentials and the Madelung-type potential due to the charge transfer. A simple physical model is proposed in order to estimate the amount of charge transfer, which has been a matter of controversy in graphite intercalation compounds. The band structure of C
8K is calculated self-consistently by the present method and the amount of the charge transfer is determined non-empirically to be 0.6. The obtained band structure is almost the same as that calculated by the tight binding method.
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Shoji Kashida
1979 Volume 47 Issue 4 Pages
1134-1140
Published: October 15, 1979
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The effect of uniaxial compressive stress upon the successive phase transition temperatures of K
2PbCu(NO
2)O
6 was investigated. The I–II transition temperature (280 K at 1 bar) increased linearly with the rate of 73±2 deg kbar
−1 for the [001] stress, 2.5±0.2 deg kbar
−1 for the [111] stress and 13.5±1.1 deg kbar
−1 for the [110] stress, and the II–III transition temperature (273 K at 1 bar) increased linearly with the rate of 10.4±0.2 deg kbar
−1 for the [001] stress, 5.8±0.5 deg kbar
−1 for the [111] stress and 7.2±1.3 deg kbar
−1 for the [110] stress, respectively. In the case of the compression along the [001] axis, the I–II transition which is of first order at the atmospheric pressure became of second order above around 0.4 kbar. The results are discussed on the basis of an orientational order-disorder model of the Jahn-Teller distorted Cu(NO
2)
6 octahedra by taking into account a coupling between the orientation of the octahedron and the bulk distortion induced by the pressure.
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Toshiharu Hoshino, Katuhisa Suzuki
1979 Volume 47 Issue 4 Pages
1141-1151
Published: October 15, 1979
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The energy bands of four diamond-type crystals C(diamond), Si, Ge and α-Sn(gray tin) are calculated employing the cluster-Bethe lattice model. The interaction integrals in the model are evaluated in the chemical pseudopotential method, with no adjustable parameters except the lattice constant. Our calculations reproduce main features of the electronic density of states obtained by the empirical pseudopotential method (EPM) and the discrete variational method (DVM). The present approach allows one to characterize the energy bands from a chemical point of view based on atomic properties. It is seen that the semiconducting band gap and the distribution of the
s and
p components depend strongly on a particular combination of transfer integrals γ
3⁄γ
2. Deviations of our result from the EPM and DVM results are discussed.
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Shin-ya Miyatani, Senzi Mori, Mihiro Yanagihara
1979 Volume 47 Issue 4 Pages
1152-1158
Published: October 15, 1979
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The phase diagram of Cu
2−δTe (δ<0.22,
T<400°C) is constructed with the help of the galvanic cell Cu|CuBr|Cu
2−δTe|C, showing that it includes as large as 10 phases in the range concerned. This diagram has been justified by DTA measurements. The electronic conductivity and ionic one are also measured.
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Kazumi Kasai, Chihiro Hamaguchi
1979 Volume 47 Issue 4 Pages
1159-1167
Published: October 15, 1979
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New method is described to investigate the damping factor \barγ which represents the exponential decay of the magnetophonon resonance amplitude in the inverse magnetic field. The method is based on measurement of the second derivative signals of the magnetoresistance utilizing magnetic field modulation technique and analysis using the empirical formula obtained by Stradling and Wood. Measurements are performed between 58 and 235 K in n-InSb with carrier concentrations 3.9×10
13∼8.3×10
14 cm
−3. The observed temperature, impurity and carrier concentration dependence of \barγ∝(
Tns2⁄
n)
1⁄4 at
T<160 K indicates that the dominant process is the band tailing effect. A shift of the extremal position to higher magnetic field is observed. The shift is found to be larger for samples with larger damping factor \barγ. A tentative interpretation for the shift is made in terms of Landau level shift induced by the real part of the electron self-energy.
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Mitsugu Yamanaka, Kiyofumi Muro, Shin-ichiro Narita
1979 Volume 47 Issue 4 Pages
1168-1176
Published: October 15, 1979
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Far-infrared magneto-plasma absorptions due to electron-hole drops (EHD) in pure germanium have been measured at quasi-continuous wavelengths from 250 μm to 1730 μm by the use of optically pumped lasers in the Faraday and Voigt configurations up to 80 kOe. The observed magneto-plasma resonances of EHD are classified into the transverse and the longitudial modes, and also into the electric-dipole and the magnetic-dipole resonance modes according to the theory by Ford
et al. We also discuss carrier mass renormalization in EHD and influence of strong magnetic field on the properties of EHD, comparing the experimental results with the theoretical calculations. The estimated value of carrier density and radius of EHD are 8×10
1.7 cm
−3 and 0.2 μm at 70 kOe, respectively.
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Ryuji Abe
1979 Volume 47 Issue 4 Pages
1177-1184
Published: October 15, 1979
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In order to know the tunneling motions in KDP and DKDP more quantitatively, the barrier height and the energy levels for proton and deuteron were investigated using a simple double square well potential. The calculation shows that the tunneling frequency for deuteron is about a fifth of that for proton, which agrees well with our experimental result. The energy differences between the ground state and the first excited state in KDP and DKDP have good correspondences to the infrared absorption lines. The barrier height was estimated to be higher than 0.1 eV and maybe about 0.2 eV. This height is fairly higher than that estimated from a few experimental results. It was shown that the dielectric relaxation experimentally observed for DKDP could be explained favourably by considering an overdamped oscillation of soft mode which was closely related with the tunneling motion of deuteron.
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Mitsuo Wada, Akikatsu Sawada, Yoshihiro Ishibashi
1979 Volume 47 Issue 4 Pages
1185-1190
Published: October 15, 1979
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The Raman scattering spectra of Rb
2ZnCl
4 single crystals were measured over the temperature range covering the successive phase transitions at
T1=302 K and
T2=189 K. The low-lying mode, whose frequency decreases as the prototypic-incommensurate phase transition point
T1 is approached from below, has been observed for the
c(
aa)
b scattering orientation as well as for the
a(
cc)
b orientation, and is assigned to the amplitude mode. The results obtained are discussed in connection with the incommensurate phase transition.
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Takamasa Kawano, Kazuo Furukawa
1979 Volume 47 Issue 4 Pages
1191-1197
Published: October 15, 1979
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Temperature dependence of EPR spectra from polar VO
2+ probes doped in ferroelectric (NH
4)
2SO
4 crystal was studied in the range between 110 K and 300K. Impurity ion, VO
2+, takes substitutionally the position of two NH
4+ ion vacancies so as to satisfy the local charge neutrality. Three kinds of VO
2+ sites in the crystal are identified. One is VO
2+ substituted for II–II pair of NH
4+ ions, another is I–II and the other is I–I.
When the temperature is lowered, VO
2+ molecular axes are slightly displaced in a different manner, respectively. From this fact it is concluded that the local electric field is reflected in the VO
2+ displacement. The analyses of the polar angles to the crystal
c-axis for VO
2+ in II–II and I–I sites show quite similar profile with anomalous temperature dependence of polarization observed by Unruh. The two-sublattice model for (NH
4)
2SO
4 is supported by the present study.
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Hiroyuki Mashiyama, Katsuhiko Hasebe, Sigetosi Tanisaki, Yoshihiro Shi ...
1979 Volume 47 Issue 4 Pages
1198-1204
Published: October 15, 1979
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Space groups and super-lattice structures of five phases of RbLiSO
4 are investigated by X-ray diffraction method. Phase I (
T>204°C) is paraelectric (
Pmcn-
D2h16). The incommensurate phase II (202<
T<204°C) is characterized by a wave number
kz=(2+δ)⁄5 with δ(
T)=0.013(204°C)∼0.137(202°C). Phase III takes
c=2
c0 structure which belongs to
P2
1⁄
c11-
C2h5, where
c0 is the cell dimension in phase I. The ferroelectric phase IV (166<
T<185°C) belongs to
P11
n-
Cs2 and takes
c=5
c0 super-structure. The I–II transition is 2nd order and the critical exponent is β=0.36±0.05, while other three transitions are 1st order ones.
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Shigeru Suzuki
1979 Volume 47 Issue 4 Pages
1205-1209
Published: October 15, 1979
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Linear thermal expansions of (NH
4)
3H(SO
4)
2 were measured both by an X-ray diffractometer and by a dilatometer in a temperature range between 100 K and 450 K covering the four phase transitions. The crystal exhibits a large anisotropy in the linear thermal expansion coefficients measured along the pseudo-orthorhombic
a0,
b0 and
c0 axes. Of thermal expansion coefficients along the three axes, the coefficient observed near but above the transition temperature
TcII(265 K) shows the largest anomalous temperature dependence along the
c0 axis. The coefficient observed near but above the transition temperature
TcIII(140 K), however, shows relatively large anomalies in the plane perpendicular to the
c0 axis.
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Ko Sugihara, Kiyoshi Kawamura, Takuro Tsuzuku
1979 Volume 47 Issue 4 Pages
1210-1215
Published: October 15, 1979
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The average mobility (\barμ) of majority carriers evaluated from the magneto-resistance of highly oriented graphite through
B2⁄(
Δρ⁄ρ
0)=(
c⁄\barμ)
2+O(
B2) is proportional to
T−1.6 between 40 K and 80 K, and
T−1.2 above 80 K. The
T−1.2 dependence was observed by Soule and is in agreement with the theory of Ono and Sugihara. The range in which
T−1.6 dependence is observed, coincides with the region where the phonon drag effect is active. This suggests us that the both phenomena are closely correlated: The phonon system receives the momentum from carriers driven by an external field. If the relaxation processes of phonons except for that due to the carrier scattering are totally inactive, the transferred momentum is partly returned to the carrier system from phonons so as to enhance the mobility.
Calculations have revealed that \barμ=(\barμ)
0(1+
CT−3) between 40 K and 80 K, where (\barμ)
0∝
T−1.2.
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Tomoyuki Takeuchi
1979 Volume 47 Issue 4 Pages
1216-1223
Published: October 15, 1979
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The plastic strain which relieves the stress concentration at the crack tip is assumed to be confined on the plane perpendicular to the crack plane. The localized plastic strain was represented by an array of edge dislocations as a first approximation. In this model the stress distribution is obtained by a superposition of stresses by the crack, the dislocations, and the interaction stress between dislocations and crack. The stress near the crack tip was corrected by taking account of the blunting of crack tip. It was concluded that the maximum value of the normal stress, or the hydrostatic component, in front of the crack tip is 3–4 times tensile flow-stress of the material independent of the applied stress intensity.
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Tomoyuki Takeuchi
1979 Volume 47 Issue 4 Pages
1224-1230
Published: October 15, 1979
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It has been shown in a previous paper that the maximum normal stress in front of a crack tip in non-hardening materials becomes 3–4 times tensile yield stress. A spherical cavity in non-hardening materials can grow when the internal pressure exceeds a critical value, which is the same order of magnitude as the maximum normal stress near the crack tip. A formula for the critical pressure in work-hardening (high-strength) materials is obtained with a modification in the calculation process of non-hardening materials. The fracture toughness (
KIC) is formulated on the assumption that the size of the region satisfying the cavity growth condition exceeds the dimple size observed on the fracture surface. The result showed that
KIC decreases with increasing yield stress.
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Yusuke Nakamura, Takashi Iwasaki, Hisawo Wakabayashi
1979 Volume 47 Issue 4 Pages
1231-1237
Published: October 15, 1979
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According to Rubio
et al., doped Eu
2+ ions took the place of Rb
+ ion in RbCl, while Kawano
et al. showed that the ions occupied the positions off Rb
+ ion site along [111] direction. After Bridgman method, we made the crystal under various conditions. Angular dependence of the ESR spectrum on magnetic field and variation of the line width with temperature were measured. The results proved that the Eu
2+ ion occupies a Rb
+ site. The obtained values of activation energy of the vacancy in NaCl, KCl and RbCl are 0.41, 0.34 and 0.32 eV, respectively. The spin Hamiltonian parameters for isolated
151Eu
2+ ions are as follows;
g=1.991,
A=−31.0×10
−4 cm
−1 in KCl and
g=1.991,
A=−31.0×10
−4 cm
−1 in RbCl. Those for
153Eu
2+ in NaCl are 1.995 and −13.0×10
−4 cm
−1.
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Akira Sugiyama
1979 Volume 47 Issue 4 Pages
1238-1245
Published: October 15, 1979
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An exact solution to the Frenkel-Kontorova equation for a one-dimensional dislocation under stress is obtained by numerical calculations, and is compared with some of approximate solutions which are calculated from a continuum model, a successive approach, the usual Peierls barrier model and the two-parabola approximation to a sinusoidal potential. The exact solution shows that i) the Peierls force is not an oscillatory but a monotonically decreasing function of the thickness of the boundary layer, and ii) of the above approximations, the usual Peierls potential barrier model is best, while the two-parabola approximation is worst. As examples of the Peierls force, an effective shear stress of the coherent twin boundary and an intrinsic coercive force of 180° Bloch domain wall are discussed.
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Teiichi Suzuki, Tadashi Itoh
1979 Volume 47 Issue 4 Pages
1246-1251
Published: October 15, 1979
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With excitation at the giant two-photon absorption band for the direct generation of excitonic molecules, a new emission band has been observed in CuCl near 3.2082 eV, which is the energy of the bottom of upper branch of
Z3 excitonic polariton. From the correlation of the emission band with the
ML emission, the new band is considered to be the emission of upper branch polariton created through the fission of relaxed excitonic molecules induced by the
ML emission.
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Sadao Hoshino, Takashi Sakuma, Yasuhiko Fujii
1979 Volume 47 Issue 4 Pages
1252-1259
Published: October 15, 1979
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The phase transitions and the crystal structures of a superionic conductor Ag
3SI were investigated by specific heat measurements and by X-ray as well as neutron diffraction methods. The transition entropies were measured to be 1.44 cal/mol·deg for the γ-β transition at 157 K and 2.71 cal/mol·deg for the β-α transition at 519 K. The least squares refinements of atomic positions and isotropic temperature factors were carried out. β-Ag
3SI is cubic with space group Pm3m in which Ag is distributed into four positions apart 0.5 A from the face centered position toward [100], while in γ-Ag
3SI below 157 K, Ag is located at one of these four positions obeying the symmetry of the rhombohedral space group R3.
From these experimental results, it was found that the nature of the successive phase transitions in Ag
3SI was not only of the order-disorder type but also of a structural phase transition. A comparison was made with the phase transition of CsPbCl
3.
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R. Anholt, D. P. Wang, Y. C. Liu
1979 Volume 47 Issue 4 Pages
1260-1267
Published: October 15, 1979
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L-subshell vacancy-production cross sections were measured in equal-velocity (0.3- to 1.25 MeV/a.m.u.) proton and deuteron bombardments of Au, Pb, Th, and U targets, allowing a unique determination of the Coulomb deflection correction factor. Corrections to the measured cross sections for the energy loss of the projectile in ionizing the inner-shell electron are made. The measured Coulomb deflection factors are compared with various theories. Previously measured Coulomb deflection factors for
K-vacancy production are re-evaluated, taking into account projectile-energy loss.
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G. P. Gupta, K. C. Mathur
1979 Volume 47 Issue 4 Pages
1268-1274
Published: October 15, 1979
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Differential cross sections for the electron impact excitation from the ground state to the 2
3S, 3
3S and 4
3S states of helium at impact energies 200 and 300 eV, are calculated in the two potential model and using the modified plane wave approximation. The results are compared with the available experimental data and other theoretical calculations. It is shown that the present procedure provides significant improvement over the plane wave approximation.
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Shinsuke Watanabe, Tu Khiet
1979 Volume 47 Issue 4 Pages
1275-1282
Published: October 15, 1979
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We examine experimentally the propagation of an ion wave under the action of a high frequency electric field with frequency close to the electron plasma frequency and an interaction between them. The interaction is characterized by the ponderomotive force. It is proportional to the gradient of a time-averaged high frequency electric field modulated by an ion wave. Experiment confirms that the modulation of a high frequency field increases linearly with the amplitude of the ion wave and with that of the high frequency field. The phase of the modulated wave with respect to the ion wave depends on a frequency of the applied field. Under the action of the ponderomotive force, the phase velocity of ion wave decreases as an injected high frequency power increases in the case where the frequency of the field is lower than the electron plasma frequency.
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Noboru Nakano, Tadashi Sekiguchi
1979 Volume 47 Issue 4 Pages
1283-1289
Published: October 15, 1979
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Experimental studies on the spontaneous generation of magnetic field associated with laser-produced plasmas from solid target have been carried out in the presence of ambient gas. The differences from the high vacuum case have become clear as for the time-dependent spatial variation of magnetic field, and the magnitude of generated magnetic field is observed to increase due to the presence of ambient gas in its rapidly expanding phase. All the experimental results thus obtained are consistent with what is called the “
magnetic field amplification.”
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Ryo Sugihara, Yukio Midzuno
1979 Volume 47 Issue 4 Pages
1290-1295
Published: October 15, 1979
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When an electrostatic wave is suddenly applied, initially trapped particles suffer a rapid, large acceleration as well as the stochastic heating, while initially untrapped particles suffer only the stochastic heating. When the bounce frequency ω
B is larger than (ω
cω)
1⁄2, the initially trapped particles mainly absorb the wave energy and form a high energy tail. The results are applied to the problem of energetic ion creation in laser fusion plasma and of a high energy tail formation in a plasma heated by the lower hybrid wave.
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B. K. Som, M. R. Gupta, B. Dasgupta
1979 Volume 47 Issue 4 Pages
1296-1298
Published: October 15, 1979
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A model equation as above (Boussinesq form) which governs the lattice wave and shallow water waves, has been reduced to a modified form of Hirota equation for intermediate range of wave number (
k<1), considering the case when the central wave number
k and the spectral width
Δk∼ε of the wave packet are both smaller than unity but of comparable magnitude. For the modified Hirota equation, the envelope soliton solution is obtained and the condition for modulational instability is derived. This is found to differ appreciably from the corresponding condition for non-linear Schrödinger equation.
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Kiyoji Nakamura
1979 Volume 47 Issue 4 Pages
1299-1304
Published: October 15, 1979
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The variational and minimum principles are presented, using Carson transform, in the linear quasi-static theory of viscoelastic solids. The first variational and minimum principles are given for the case in which the stress-strain relations are in relaxation integral form. The second principles are given in creep integral form. In the presented principles the viscoelastic solids are allowed to be inhomogeneous and anisotropic.
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Toyoko Minota
1979 Volume 47 Issue 4 Pages
1305-1312
Published: October 15, 1979
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The shock wave structure of a dusty gas containing particles of two different sizes is numerically investigated on the basis of the Boltzmann equation for a gas-particle mixture, and of a differential approximation for radiative heat transfer. For strong radiation, the temperature profiles of two particle clouds resemble each other, although their absorption coefficients are different. The radiative heat flux is always in the opposite direction to the gas flow. For weak radiation, if the difference of the absorption coefficients of two particle clouds is very large, the disagreement of their temperature profiles is remarkable. There appears behind the gas shock front a particular region in which the radiative heat flux is in the same direction as the gas flow, and the relaxation length to the final equilibrium state becomes shorter than the case without radiation.
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Iwao Harada
1979 Volume 47 Issue 4 Pages
1313-1320
Published: October 15, 1979
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The compressibility effect on a mechanically induced unsteady Ekman layer has been investigated by using the boundary layer theory. The analytic solution is obtained for the case in which the Prandtl number is equal to unity. It is found that the period of the inertial oscillations expressed by the Fresnel integral
S(2σ
2τ) becomes short as the compressibility is increased, and the unsteady Ekman layer of a compressible fluid (σ>1) reaches the steady state faster than that of an incompressible fluid (σ=1). Here σ is the compressibility parameter and time τ is nondimensionalized by an inverse of the angular velocity
Ω−1.
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Masaki Takashima
1979 Volume 47 Issue 4 Pages
1321-1326
Published: October 15, 1979
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The problem of the onset of surface tension driven instability in a horizontal layer of binary liquid mixture subjected to a vertical temperature gradient is examined using linear stability theory. The solute is assumed to be a non-surfactant and the Soret effect is taken into account. Assuming that the neutral state is a stationary one, the conditions under which instability sets in are determined in detail and it is found that the presence of the solute can play a prominent role through the Soret effect.
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Tutomu Kawata, Tamotsu Morishima, Hiroshi Inoue
1979 Volume 47 Issue 4 Pages
1327-1334
Published: October 15, 1979
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Classical solutions of the two-dimensional massive Thirring model with laboratory co-ordinates are obtained exactly by the inverse scattering method. The Gel’fand-Levitan integral equations appearing with tedious nonlinearities are treated systematically for the case of discrete spectrums and the
N-soliton solution is obtained with closed forms. The two-soliton solution is detailed and the collision between solitons is made clear.
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Akira Nakamura
1979 Volume 47 Issue 4 Pages
1335-1340
Published: October 15, 1979
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The Bäcklund transform, existence of infinite number of conservation laws and the inverse scattering transform scheme are found for the Benjamin-Ono equation that describes nonlinear internal waves in a stratified fluid.
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Shin’ichi Oishi
1979 Volume 47 Issue 4 Pages
1341-1346
Published: October 15, 1979
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A method is presented for constructing generalized soliton solutions of multiple solitons in a background of ripples for certain bilinear differential(-difference) equations, which are transformed forms of nonlinear wave equations. It is shown that if the bilinear soliton equations have
N-soliton solutions they also have generalized soliton solutions.
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Nobumasa Takemitsu, Yaso’o Matunobu
1979 Volume 47 Issue 4 Pages
1347-1353
Published: October 15, 1979
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An exact solution of the unsteady Navier-Stokes equation is given, which represents viscous flow impinging obliquely on an infinite flat plate oscillating in its own plane. The flow field is analyzed in two coordinate systems, one being fixed in space and the other moving with the oscillating plate. The result expressed in terms of moving coordinate system provides useful information about the structure of the periodic stagnation-point flow.
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Yaso’o Matunobu
1979 Volume 47 Issue 4 Pages
1354-1360
Published: October 15, 1979
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The two-dimensional flow, induced by a point source at a finite distance from an infinite plane wall, is analyzed on the basis of the Navier-Stokes equation in the following two cases. In the first case, the source strength is considered to oscillate sinusoidally with the vanishing Reynolds number (unsteady Stokes flow). The wall shear stress can then be evaluated for arbitrary values of the frequency
Ω and is found to increase in proportion to \sqrt
Ω as
Ω becomes large. In the second case the steady flow with not-zero but small Reynolds number is dealt with by the perturbation method. It is found that the first-order perturbation to the steady Stokes solution is fairly small but that the back flow may occur far away from the stagnation point.
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Ikuo Ono
1979 Volume 47 Issue 4 Pages
1361-1362
Published: October 15, 1979
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A more realistic looped tree-like Ising lattice than a cactus tree is newly proposed. In these lattices polygons of bonds are connected with each other through not a single vertex but a common side. For a pure Ising ferromagnet with hexagonal loops, transition temperature is rigorously obtained as
kBTc⁄
J=0.864. Random bond mixtures are also rigorously treated.
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Ken-ichi Kumagai, Yuji Inoue, Kunisuke Asayama
1979 Volume 47 Issue 4 Pages
1363-1364
Published: October 15, 1979
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A small specific heat jump at superconducting transition in YRh
4B
4 and small magnetic contribution to the entropy in magnetically ordered state in RRh
4B
4 (R=Tb, Dy, Ho and Er) have been observed. Hyperfine field of Gd in GdRh
4B
4 is largly anisotropic forming a powder pattern in NMR spectrum. The broadened NMR spectra of
11B are observed in the magnetically ordered compounds. The polarization of the conduction electrons at B site is found to be very small.
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Haruki Kawamura, Kyoji Tachikawa, Kenichi Takemura, Shigeru Minomura
1979 Volume 47 Issue 4 Pages
1365-1366
Published: October 15, 1979
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The bulk modulus of A-15 Nb
3Ge was determined from the lattice constant changes due to the pressure. The determined value is about 1150 kbar, and is rather small compared with the value of V
3Si.
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Ichiro Kato, Yoshio Kaneko, Tadaoki Mitani, Takao Koda
1979 Volume 47 Issue 4 Pages
1367-1368
Published: October 15, 1979
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The magnetization measurements have been made on the solid solutions of EuS
1−xSe
x. The experimental magnetic phase diagram for this random spin system is interpreted by taking account of the exchange mechanism in the mixed Eu-chalcogenides.
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Yasuaki Nakagawa, Mitsuhiro Inazumi, Noboru Kimizuka, Kiiti Siratori
1979 Volume 47 Issue 4 Pages
1369-1370
Published: October 15, 1979
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Two-step phase transitions are found in stoichiometric YFe
2O
4 at low temperatures, about 230 K and 190 K during cooling. A hexagonal lattice at room temperature is distorted to be monoclinic and subsequently triclinic. No parasitic ferrimagnetism is found in YFe
2O
4.00, in contrast to oxygen-deficient specimens such as YFe
2O
3.94.
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