The neutron to proton ratio (R) on the surface of heavy (Ag, Br) and light (C, N, O) nuclei of emulsion has been re-evaluated in an experiment based on the sample of 20,000 K⁻-captures in emulsion which include 13,800 interactions used earlier which indicated R=2.9±0.3. Experimentally events are classified only into categories, one with recoils and the other without recoils. Exhaustive Monte-Carlo calculations are made for simulating K⁻-captures by single and double nucleons on heavy and light nuclei of emulsion. The results have been used for evaluating the frequencies of K⁻-captures by neutrons and protons on heavy and light nuclei. The value of R is found to be ∼1±0.5. This value is much lower than those reported so far.

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A new infinite group was discovered which specifies all the types of Bravais lattices as its finite subgroups. This provides the principle to classify the Bravais lattices in a mathematically unambiguous way.

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By assuming an attractive potential between molecules which depends on their relative orientations and respective molecular configurations, the phase transitions in the system of flexible molecules are studied in a mean field approximation. For simplicity, a two state model is adopted, where all configurations of a molecule are simply classified into “long” and “short” cases. It is found that the orientational transition is accompanied with a certain change in the molecular configuration for the case of long and flexible molecules (type I), whereas with a much smaller change in the case of short and rather rigid molecules (type II). In the intermediate case, transitions of the type I and II occur successively. Transitions observed in lipid membranes and in nematogenic homologous series can be understood on the basis of these analyses.

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By means of symmetry-breaking potential method originally due to Kramers and Opechowski, the free energy of binary alloy with the b.c.c. type lattice is obtained. The calculation is made up to the fifth order in an expansion into power series of a parameter ξ=tanh (βJ), where J denotes the pair interaction energy between the nearest neighbouring sites. The phase transitions are found to be always of second order through whole range of the mole fraction and in all stages of first to fifth order approximations. The transition temperature and temperature dependence of the order parameter and of the specific heat are obtained and shown diagrammatically. By neglecting terms higher than third or fourth order with βJ, the results reduce to those previously obtained by other authors.

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The nematic-smectic transition in the system of completely aligned hard cylindrical rods is investigated, by making use of the method of symmetry breaking potential. In the second virial approximation the transition is found to occur in the 3-dimensional system but not in the 1- and 2-dimensional systems, in contrast with the result obtained by Wadati and Isihara that the 2-dimensional system also exhibits such a transition. It is shown that the transition is very like the second order one. A shape effect is also studied. Furthermore, by introducing an isotropic attractive intermolecular force, the dependence of the transition on the strength of that force as well as the length and diameter of the rod molecule is investigated.

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The notation for species or ferroic point groups in the specific sense and the notation for subspecies or ferroic point groups in the subspecific sense were completed in respective previous papers. In the present paper, the notation for ferroic point groups in the rigorous sense is completed. And also, the ferroic point groups in the usual, specific, subspecific and rigorous senses derived from each of the 31 prototype point groups are all brought together into one and the same table for the sake of convenience.

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Measurements of a half-field transition in the EPR spectrum in the one-dimensional salt Cu(C₆H₅COO)₂·3H₂O are presented and compared with the theory developed by Komatsubara and Nagata. The theory accounts in a satisfactory way for the observed anisotropic feature of the non-Zeeman resonance at room temperature. The temperature dependence of the transition is found to be consistent with the theory, too.

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Magnetization, magnetostriction and magnetic anisotropy of Fe₃Pt Invar alloys were investigated by changing the degree of long range order. The anomalous behaviour was found in magnetostriction and magnetic torque curves in the ordered Fe₃Pt alloy at low temperatures. These anomalies are interpreted in terms of the reversible martensitic transformation caused by magnetic energy change.

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The magnetic properties and the phase diagram of the solid solution Co_xFe_1−xCl₂2H₂O are analyzed by using a model Hamiltonian with the mean field approximation. The results are in good agreement with those of experiments. It is concluded that the new phase which is found for x∼0.5 at low temperatures is the oblique antiferromagnet (OAF) predicted by us. A comment on the phase diagram of K₂Mn_xFe_1−xF₄ is also given.

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In a magnetic field along the c axis, ErCrO₃ undergoes the field-induced spin reorientation of a first-order nature with a displacement of a phase domain wall. To investigate the nature of the wall, the ac susceptibility has been measured for both the in-phase and the 90° phase-shifted components as a function of the applied field.
A phenomenological approach is given to the problem of a distribution of relaxation times. The dispersions of the movement of the wall are well described by the Debye formula with relaxation times of 1.3 ms and 1.9 ms at 1.8 K and 4.2 K, respectively. At the early stage of the reorientation, the relaxation time increases by the factor of three.
It is shown that the phase-domain wall has no inertia and the motion of which is insensitive to a local inhomogeneity.

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The low temperature specific heat was measured in βMn metal and alloys with V, Cr, Fe, Co and Ni. The large enhancement of the electronic specific heat due to spin fluctuations is observed. The coefficient of the electronic specific heat, γ, changes with the excess number of the d electrons per atom in the alloy, Δn_d, having a peak at Δn_d=0.005 which indicates that pure βMn remains paramagnetic even at 0 K. The behavior of the electronic specific heat is explained well qualitatively by the self-consistently renormalized spin fluctuation theory by Hasegawa.

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The magnetic moment of atoms is calculated as a function of the atomic composition on the nearest-neighbor shell, of the alloy concentration, and of a short-range-order parameter for Fe–Ni alloys in bcc and fcc phase and Fe–Co alloy in bcc phase, by use of an effective medium theory developed by Miwa and the author. The intra-atomic electron-electron interactions are assumed to be treated within the Hartree-Fock approximation, and the effective medium is determined self-consistently. The behavior of the moment caused by the change of local environment is explained in terms of the total and local density of states on the basis of numerical calculation. In a saturated ferromagnet the width of the distribution of the moment must be small for each constituent. In an unsaturated ferromagnet this width is allowed to become large.

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The effect of spin fluctuations on the ultrasonic attenuation coefficient is studied on the basis of the previously developed theory of the helical spin structure in the itinerant electron systems. The observed double peak structure in the attenuation coefficient as a function of the temperature under a rather high magnetic field is explained as due to the existence of the Stoner boundary and the mixing between up and down spin electrons due to helical ordering, which reflect themselves significantly on the low frequency part of the dynamical susceptibilities.

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By using the method developed by Kaburagi and Kanamori (Progr. theor. Phys. 54 (1975) 30) the ground state ordered structures and the conditions for their existence for the case of BCT substitutional binary alloys were obtained, which can be applied to the case of BCC based interstitial binary alloys. The method of graphical solution of the problem were devised. The six kinds of pairwise interactions, J₁, ···, J₆ were assumed. For the case of J₄=J₅=J₆=0, the problem could be solved completely for the whole range of solute concentration. The other two important cases of J₅=J₆=0 and J₁, J₂>>|J_i| (i≠1, 2) were also solved completely but for the range of low concentration. Almost all the structures experimentally observed could be obtained and the conditions for their existence were determined.

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Non-doped and Gd₂O₃-doped KTaO₃ single crystals were grown under various conditions of soaking time. It is found that KTaO₃ becomes semiconducting only for a long soaking procedure exceeding 24 hrs for both the non-doped and for the Gd₂O₃-doped crystals. It is concluded that the conduction electrons originate from oxygen vacancies acting as a donor in both crystals.
Hall coefficient, electrical resistivity, Seebeck coefficient and specific heat were measured between liquid helium and room temperatures.
The results suggest that many valley TO mode lattice scattering predominates below 200 K, and LO mode and intervalley mode lattice scattering predominates near room temperature besides TO mode.

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Infrared transmission spectra of ZnO particles, whose diameters are much smaller than the wavelength of incident light, surrounded by various dielectric media with different dielectric constant have been measured in the photon energy region from 300 to 600 cm⁻¹. Four transmission peaks were found in the photon energy region between ω_TO (E⊥c: 406 cm⁻¹, E⁄⁄c: 377 cm⁻¹) and ω_LO (E⊥c: 589 cm⁻¹, E⁄⁄c: 575 cm⁻¹), which showed features specific to the surface phonon modes. By taking account of both the optical anisotropy and the actual shape of particles, these four peaks were identified to be surface phonon modes of spherical (F), cubic (c) or cylindrical (cy) particles; ω_F^⊥ mode, ω_c^⁄⁄ mode, ω_cy^⊥ mode and overlapped peak of ω_c^⊥ and ω_F^⁄⁄ modes, where the symbols ⊥ and ⁄⁄ stand for the correlation between the crystal axis and the electric field component of the incident light.

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Magneto-transmission measurements by a strip-line method have been carried out on p-type PbTe whose hole concentration is 3×10¹⁸ cm⁻³ at 4.2 K, in the wavelength range of 96.5 to 513.2 μm using an optically pumped far-infrared laser. It is shown that the observed transmission minima correspond to the dielectric anomaly of the ordinary ray. The frequency dependence of the lattice dielectric constant has been obtained using the reported values of the effective mass parameters. The result leads to the best fit values of the parameters: ε₀=1300, ε_∞=33 and ω_TO=18 cm⁻¹.

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The temperature dependence of electric field gradient (EFG) at Rb site in RbH₃(SeO₃)₂ is studied by the second order quadrupole shift. The number of inequivalent Rb sites in the paraelectric and the ferroelectric phases agrees with that deduced from the consideration based on the crystal symmetry. It is found that the change in EFG caused by the phase transition behaved as the order parameter did. The existence of the intermediate incommensurate phase could not be confirmed.

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The nucleation and growth of ferroelectric domains in a c-plate of BaTiO₃, partly covered with electrodes, has been studied by X-ray topography. By the application of an electric field of 2.8 kV/cm for 10 seconds, small domains of several microns in size are formed outside the electrodes. On further applications of electric field, some of these nucleated domains does not grow and disappeares after the electric field was removed. By the detailed observation it is concluded that domains are not nucleated spontaneously but at the preferential points in the plate, and domains which were effective for further growth are that nucleated under the surface covered with the negative electrode. Once a nucleus has grown into a needle-like domain, new domains are easily formed around the pre-existing domain, and as the results a cluster of needle-like domain is formed.

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Investigation is made on how ion mobility in fluid is influenced by the long-wavelength fluctuations of fluid. It is shown that the effect of the long-wavelength fluctuations on the mobility depends upon the ion mass; the motion of ions with mass lighter than a certain characteristic value is not influenced by the decay of the long-wavelength fluctuations, but that of heavier ions is influenced by it. This effect, however, is smaller than influence of the small-wavelength fluctuations on the mobility, except in the case of electrons and positrons. Near the critical point, the effect of the critical fluctuations on the mobility is considered, including the effect of the decay of the critical fluctuations.

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Ag_1−δCuSe is a mixed conductor, in which Ag⁺ and Cu⁺ ions, electrons, and holes are mobile. It transforms from the β phase to the α phase (superionic phase) at 200°C and melts at 780°C. The electronic and ionic properties in these three phases are studied with the help of the galvanic cell Ag|AgI|Specimen|Pt in the range of the temperature 100∼1000°C and of the composition δ=0∼1%.

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Diffusion constant of light particles in b.c.c. lattice is calculated on the basis of the self-trapping model. The hopping and the coherent motions of the particles are treated equally by extending the method of density matrix used by Kagan and Klinger in order to take account of the existance of several interstitial sites in a unit cell. With decrease of temperature, the diffusion constant shows an activation type decrease due to the hopping motion and turns increasing owing to the coherent motion. Temperature dependence of the hopping rate and role of an intra-site perturbation as a dominant scattering mechanism of the coherent motion are discussed in detail. It is shown that recent experimental results on spin relaxation time of positive muon in pure Iron can be understood in terms of the under-barrier hopping and possibly the coherent motion.

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Spin relaxation time of positive muon diffusing by means of the hopping and the coherent motions in ferromagnetic b.c.c. Iron is calculated. With decrease of temperature, the relaxation time decreases in proportion to the diffusion constant, but it deviates from this behavior below about 100 K owing to an onset of the coherent motion and finally it again decreases in inverse proportion to a lifetime of band states formed by the coherent motion, whereas the diffusion constant simply turns increasing. The spin in a band state feels a definite magnetic field because of periodic internal fields and sees various fields when scattered to other band states. These scattering processes result in the motional narrowing. A comparison with experiment shows that positive muon in pure Iron performs the coherent motion with a mean-free path being several times as long as the lattice constant.

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A theory is presented on effects of periodic substrate potential on the two-dimensional structure of rare gas monolayers physisorbed on graphite, and the transition between the nonregistered (NR) and registered (R) phases is discussed. The present formulation takes into account, in a natural way, the two-dimensional hexagonal dislocation network structure as well as the orientational epitaxy of monolayers. For realistic values of parameters the theory predicts successive transitions from a rotated NR phase to the R phase via an NR phase without rotation. The results are in accord with recent LEED experiments on Kr and Ar.

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Thermal glow curves of KCl crystals containing 0.2∼4.2 mole% of TlCl are measured after X-ray irradiation at 77 K. Trapped electron and trapped hole centers such as Tl⁰, Tl²⁺, Tl₂⁺, (Tl₂⁺)′ and Tl₂³⁺ centers are found to be concerned in the thermal glow phenomena. The features of the glow curves change remarkably with TlCl concentration because of marked reduction in the activation energies of the trapped electrons in a crystal containing more than 0.4 mole% of TlCl. This suggests that the bottom of the conduction band is disturbed by the influence of impurity potential. The emission spectrum of the glow also changes with TlCl concentration. A new emission band comes out around 500 nm and becomes dominant above 1 mole%. It is considered that trapped hole centers with complex structures take part in the electron-hole recombination process in such a heavily doped crystal.

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In X-ray irradiated KCl crystals containing more than 1 mole% of TlCl, ESR signals of Tl₂³⁺ centers which are characterized by g=2.04 have been newly observed. This pair center has a 6s hole whose wavefunction is almost localized on one of the thallium ions (hyperfine constant A=105 GHz), and only a little fraction (about 1%) of the wavefunction is distributed on the other thallium ion (A′=1.0 GHz).
Further investigations suggest that this trapped hole center is associated with a trapped electron center and exists in the form of (Tl₂³⁺−Tl⁰). Another kind of associated center (Tl₂⁺−Tl²⁺) is also inferred to exist. The two kinds of associated centers are thermally more stable than any other trapped electron centers and trapped hole centers.

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Absorption and photoluminescence (P.L.) spectra of Cr-doped CdIn₂S₄ have been measured in visible and near infrared region. The oscillator strengths of the Cr absorption bands were found to be almost constant for all the samples having different Cr concentration. The ligand field parameters were estimated as Dq=1490 cm⁻¹, B=310 cm⁻¹ and C=3500 cm⁻¹. It is observed that fine structures of the P.L. band include several lines concerned with nearest neighbor pair.

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Raman spectra for Ln₂O₂S: Eu (Ln=Lu, Y, Gd and La) have been measured at room temperature. The observed four Raman lines are divided into low and high-frequency groups, each consisting of A_1g and E_g modes in representations of D_3d crystal point group. The high-frequency lines shift toward low frequency with increasing unit cell volume, and the low-frequency lines decrease in frequency with increasing crystal mass. The Raman active modes are assigned as even vibrations of the Ln₂O₂ parallelogram in the unit cell on the basis of the factor group analysis. The Raman lines shift continuously with increasing Eu concentration in Y_2(1−x)Eu_2xO₂S and no additional mode appears. This fact indicates that the mixed oxysulfide crystal is not a mixture of the lattices of its components, but a unique lattice.

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Doublet structure in the 5.76 eV absorption band of thallium activated KDP single crystals has been investigated at various temperatures between 4.2 K and 346 K. Its temperature dependence indicates that the structure is closely related to the ferroelectric properties of KDP. Energy separation of the doublet components is proportional to \sqrtT above the transition point T_c. This signifies that the structure is caused by the dynamic Jahn-Teller effect in the degenerate excited state. The structure below T_c, however, is due to the static crystal field, symmetry of which is reduced by the ferroelectric transition. Peculiar variation of the separation in a narrow temperature range immediately below T_c seems to reflect lattice deformation through the phase transition.

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The temperature dependence of the viscosity for the systems polystyrene-cyclohexane, polystyrene-methylcyclohexane and poly(p-chlorostyrene)-propylbenzene near the Flory θ temperature is investigated. The following two results are obtained for the polystyrene systems: 1. Expansion factor α is not a single-valued function of the usual excluded volume parameter z except for M\gtrsim10⁶ and this result cannot be attributed to partial draining effects which were adopted by Berry. 2. The plots of (α_η³−1) vs z are two lines intersecting slightly below the θ temperature. The fact 1 is discussed in terms of departure from Gaussian distribution. Relation between the fact 2 and the globule-coil transition is also discussed.

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Complex coacervation is explained with the assumption that the symmetrical aggregate polymer (SAP) model is applicable to both dilute and concentrated phases. An interaction potential between SAP’s is obtained in a way similar to the derivation of the Flory-Krigbaum potential between usual polymers. Using this potential, osmotic pressure P is obtained by the virial expansion method. The curve of P (vs volume fraction of SAP) corresponds to the curve of pressure (vs volume) representing gas-liquid phase separation. Moreover the self-suppression is quantitatively explained by the contraction of SAP dimension.

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Higher order contributions in the reductive perturbation theory have been reexamined for the nonlinear ion acoustic wave propagation under the periodic boundary condition. The boundary condition gives rise to renormalization terms which enable us to eliminate secular contribution in the higher order terms.
As a result of analysis carried up to the second order, the ion flux associated with propagation of nonlinear ion acoustic cnoidal wave is examined for various values of excitation frequencies. It has been shown explicitly that the dependence of the ion flux on the wave amplitude becomes much weaker than that of quasi-linear theory at lower frequency. This illustrates that the averaged properties such as the averaged flux in genuine nonlinear systems depend on their nonlinear behavior in very crucial way. Range of validity of so-called quasi-linear approximation appears to be restricted to very small amplitude of disturbance.

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This paper deals with weakly nonlinear hydromagnetic waves propagating along an external magnetic field in a plasma of cold ions and isothermal electrons in the presence of effective electron-ion collisions. By means of a nonlinear perturbation method, a single equation which describes the asymptotic behavior of the waves is derived. It is shown that this equation admits steady state solution corresponding to the limit shock in conventional magnetohydrodynamics.

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An analytical investigation of the second order thermal boundary layer in an incompressible plane flow past a curved surface with uniform heat flux is carried out to study the effects of body curvature and free-stream vorticity on heat transfer. The application of the present theory to heat transfer problems is shown by considering the symmetric uniform shear flow past a flat plate and the potential flow past a circular cylinder.

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An exact solution to “simple harmonic generation” is obtained by using the direct method. The solution indicates a breakdown of the Zakharov-Shabat eigenvalue problem.

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Two-dimensional slow viscous flow due to an arbitrary translation of a cylinder on the center-line of a wedge is studied on the basis of the Stokes approximation. Drag on the cylinder and the velocity field are calculated up to the first-order effect of the presence of boundaries by the use of a two-dimensional method of reflections.

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This paper provides photographs of separating Stokes flows. Silicone oil and glycerine were used as the working fluid. The aluminum powder method and the glass beads method were used for flow visualization. The flows studied are flows around bodies placed in a uniform flow, flows past bodies placed near a plane wall, flows past a fence, flows past a step, flows past a wall cavity, and flows near a sharp corner. It is found that there is a remarkable agreement between the experimental results and the theoretical ones.

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The magnetic susceptibility of the first stage potassium graphite intercalation compound, of which the host graphite was grafoil sheets, was measured by the Hartshorn bridge method. The superconducting transition temperature of C_8.8K was found to be 125 mK. The susceptibility fluctuation in the transition region was examined with Aslamazov-Larkin’s theory, and the dimensionality in the transition region gradually changed as temperature was decreased toward T_c.

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Magneto-electric effect was measured in a temperature range between 4.2 and 30 K on a plate of Fe₃O₄ cut parallel to (110) referred to the cubic axes. The voltage as high as several tens of volts was observed to be induced across a 1.45 mm thick specimen when the magnetization is rotated in the (110) plane at 4.2 K. The effect changes drastically as the temperature is increased towards 10 K, at which a specific heat anomaly had been reported.

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A theory of EPR in one-dimensional systems exhibiting the effect of low-symmetry of spin arrangement is proposed. The calculated results for TMMC agree well with new measurements in the dependences on polar and azimuthal angles of the chain axis in the coordinate system where the direction of static field is taken as polar axis.

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Nonlinear magnetization, m=χ₀h+χ₂h³, was found in spin glass using a mutual inductance bridge. The susceptibility χ₀ showed a cusp at T_g as usual, on the other hand χ₂ behaved like a divergence at T_g.

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Photoluminescence, absorption and electron paramagnetic resonance spectra of Co-doped CdIn₂S₄ have been investigated. These measurements are interpreted on the basis that CdIn₂S₄ is a partially inverted spinel and confirm that the Co²⁺ ions are present in both octahedral and tetrahedral coordination as expected.

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The reexists the model proposed by Labbé and Friedel to explain the structural transformation in V₃Si. In their model, it is assumed that the electronic states in the three kinds of vanadium linear chains can be expressed as the tight-binding bands. An influence of the coulomb interaction between the electrons on this model is investigated with the aid of the Hubbard model. It is deduced that the magnitude of the coulomb interaction in the system described by Labbé and Friedel’s model is considered to be small within the framework of Kanamori’s approximation.

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Brillouin scattering spectra of K₂SeO₄ were observed near the paraelectric-incommensurate phase-transition temperature T₂ (129.5 K). The velocity of longitudinal hypersonic wave propagating along the [001] direction shows an anomalous temperature dependence around T₂, while along the [100] and [010] directions, the velocity shows no anomaly.

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A new polar phase (phase VI) is induced in RbLiSO₄ by the external electric field. The cell dimension of phase VI is tripled in comparison with phase I (c=3c₀) and the space group is P_21cn−C_2v⁹, the same as that of the ferroelectric phase of K₂SeO₄. In the temperature range of phase II and III, the ferroelectric phase IV is realized at first with increasing the field, and finally a new phase appears. The phase diagram is determined by X-ray scattering.

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Isochronal annealing for copper single crystals, electron-irradiated at temperature below 90 K, was investigated in stage II, III and IV temperature ranges. The yield stress increase was observed on the annealing in the temperature range of 90 K<T_ann<330 K, and the yield drop phenomenon was also observed on the annealing in the temperature range of 100 K<T_ann<230 K.

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The propagation of space-charge neutralized pulsed ion beams across the magnetic field was studied experimentally. The beam was generated by a reflex triode, and the ion energy peaked at 130 keV. A transverse magnetic field B_⊥ of up to 3 kG was applied to the drift tube over a distance of 20 cm. The maximum ion current density was approximately 10 A/cm² at the entrance of this region. The beam was not impeded by the magnetic field for B_⊥\lesssim2 kG in agreement with a theoretical prediction.

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A new scheme of the inverse scattering method is proposed. As an illustration of novel feature of our scheme, the set of fundamental equations has been presented for a generalized nonlinear Schrödinger equation, of which nonlinear terms are composed of a usual cubic nonlinear term and a derivative cubic nonlinear term.

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