The decay of ¹²⁴I was investigated with beta-ray spectrometers and scintillation spectrometers by using carrier-free source produced by ¹²¹Sb (α, n) ¹²⁴I. The intensity ratio of the 1.54 MeV beta component to the 2.15 MeV one was obtained to be 1.07. Internal conversion ratios for the 604 keV gamma transition are K/L=7.3±0.4 and (M+N)/L=0.26±0.07. Internal conversion coefficients were determined to be (3.8±0.6)×10⁻³, (2.5±0.4)×10⁻³, (7.9±1.5)×10⁻⁴, (3.3±0.8)×10⁻⁴, (2.9±0.7)×10⁻⁴, (2.1±0.4)×10⁻⁴ and (2.1±0.8)×10⁻⁴ for gamma transitions of 0.604, 0.72, 1.32, 1.37, 1.52, 1.69 and 2.08 MeV, respectively. The coefficient A₂(W) in the directional correlation function (Remark: Graphics omitted.) was measured for the 2–(1.54 MeV β)2⁺(0.604 MeV γ)0⁺ cascade. The result is discussed on the basis of the ξ approximation, the modified B_ij approximation and a more accurate method.

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A theory of the Raman scattering of light due to spin systems in magnetic crystals is developed by using the spin dependent electric polarizability. The polarization characteristics of the scattering, the scattering intensity and its temperature dependence are treated with particular referenc to antiferromagnetic iron group fluorides, where one- and two-magnon scatterings have been observed. Agreement between the theory and the experimental results is satisfactory.

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Analytic solutions to the equation of motion in anharmonic one-dimensional lattice are given. Wave-trains and solitary-waves which propagate in the lattice are studied with reference to the limiting cases of the system of hard spheres and to the continnm limit.

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Magnetization of RCd (R=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er or Yb) has been measured between liquid helium and room temperatures. Sound specimens were obtained only by using excess amounts of R. Lattice parameters obtained from X-ray powder diffraction were in agreement with those by Iandelli. The compounds are ferromagnetic except for PrCd, SmCd and YbCd. PrCd may be antiferromagnetic; YbCd is paramagnetic. SmCd exhibits quite peculiar behavior; diamagnetic below 110°K and paramagnetic above. Anomalies were found in the thermomagnetic curves of ferromagnetic TbCd and DyCd, at 55°K and 40°K respeclively. Paramagnetic moments per R calculated from the slope of 1⁄χ–T curves are in general agreement with those of R⁺⁺⁺, except for the case of Yb.

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It was studied theoretically whether a periodic modulation of the spin configuration along the extended stripes of the stripe domain walls lowers the total energy or not. So long as the films of critical thickness are concerned, the asymptotic solution shows that the modulation of that kind is not favored from the view point of the optimal energy.

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A series of Cr₂₃C₆-type borides was investigated by means of thermomagnetic measurements. The atomic magnetic moment (Curie temperature) of (Fe, Co)₂₀Al₃B₆ increases linearly from about 0.6 Bohr magnetons (403°K) for Co₂₀Al₃B₆ to a value of 1.5 Bohr magnetons (815°K) for Fe₈Co₁₂Al₃B₆. Partial replacement of the Ni in non-magnetic Ni₂₀Al₃B₆ by Fe also causes a smooth increase in moment (Curie temperature) and gives a value of 0.5 Bohr magnetons (285°K) for Fe₈Ni₁₂Al₃B₆. (Co, Ni)₂₀Al₃B₆ exists in a perfect solid solution and shows a peak in moment (Curie temperature) vs. composition curve at about Co₁₇Ni₃Al₃B₆.
These results can be accounted for in terms of an idea in which new magnetic moment is induced in these systems.

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The Heisenberg model, the Ising model and the xy model in ferromagnetism are treated within a unified scheme. The exchange interaction between nearest neighboring spins i and j is −(J⁄2)[aσ_i^zσ_j^z+b(σ_i^xσ_j^x+σ_i^yσ_j^y)], where J is the exchange integral, σ_i the Pauli spin operator of the i-th spin, and a and b are parameters varying from 0 to 1, respectively. The high temperature series for the susceptibilities of linear chain, simple quadratic and simple cubic lattices are calculated up to the seventh order of J⁄kT. Padé approximation is applied to find the Curie point and the power of the singularity of the susceptibility. In the case of a=1 the Curie point is almost constant in the region 0≤b\lesssim0.7 for simple quadratic and 0≤b\lesssim0.8 for simple cubic lattice, respectively, but the convergence of Padé approximation becomes worse as b approaching 1.

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Thermal conductivity measurements at 298°K have been made on a series of antimony-arsenic alloys with arsenic concentration up to 60 atomic percent. In a central range of the composition the lattice thermal conductivity was found to increase anomalously. The results are discussed on the basis of Klemens-Drabble theory. It is suggested that the increase in lattice thermal conductivity, is attributable to a possible existence of the ordered alloy SbAs in Sb–As system.

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Correlations among the changes in optical density due to illumination with uv, 425-, or 540-mμ light have been examined of the uv, 390-, 425-, and 540-mμ bands introduced by neutron irradiation in ZnS single crystals. The photosensitive behavior before and after isochronal annealing of the samples and the analysis of the intensity distribution of the 425- and 540-mμ bands reveal that the 425-mμ band consists of a broad and narrow bands, and that this broad band and the 540-mμ band may have the same origin of absorption, The narrow 425-mμ band and the 390-mμ band disappear by isochronal annealing up to 340° and 480°C, respectively. The photosensitive uv band and the other visible bands begin to disappear from the step at 520°C. Activation energy for the defects responsible for 540-mμ band has been estimated to be 2.2 eV. A reasonable placement of the energy levels has been made of these absorption centers.

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The paramagnetic resonance spectra of Mn²⁺ ions in single crystals of CsBr were studied at 9 and 35 GHz. Two different kinds of spectra were observed, which arise from Mn²⁺ ions in two different environments; one is a Mn²⁺ ion in an aggregated state, and another is a Mn²⁺, which substituted Cs⁺ and is accompanied with a positive ion vacancy in a nearest neighbor cation site. The spin Hamiltonian constants of the spectrum corresponding to the latter were found as g_⁄⁄=1.95±0.02, g_⊥=2.00±0.02, D=0.390±0.02 cm⁻¹, A=(90+2)×10⁻⁴ cm⁻¹.

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The interaction between bivalent manganese ion (Mn²⁺) and oxygen vacancy with a captured electron (F-center) in BaTiO₃ is investigated via electron spin resonance (ESR). The resonance intensity of hyperfine structure (h.f.s.) of Mn²⁺ decreases with the degree of reduction. The fine structure is not observed in strongly reduced specimens. The narrowing and broadening of line widths of the h.f.s. in reduced crystals are observed below room temperature and above Curie temperature, respectively. The hyperfine splittings in reduced specimens are slightly less than those in unreduced ones.
The changes of ESR spectra in reduced crystals are reasonably explained in terms of the interaction between Mn²⁺ and the F-center.

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The electron spin resonance of F³⁺ in single crystals of SrTiO₃ has been studied in the low temperature phase below 110°K. The resonance lines exhibited small splitting in addition to the usual tetragonal splitting. The orientation dependence of the splitting was measured at 77°K and at 4.2°K. The whole spectrum is explained to be due to the rotation of oxygen octahedron in the (100) plane, the angle of rotation being 1.4° at 77°K and 2.1° at 4.2°K. Corresponding splitting was also observed for the case of the ‘strong axial field’ spectrum due to Fe³⁺ accompanied by the nearest neighbor oxygen vacancy. The observed angles of rotation are about 30 percent smaller than those of the former case. The crystal structure deduced from the atomic positions of oxygen ions will be D_4h¹⁶ in the low temperature phase. Correlation with the resonance data of Gd³⁺ in SrTiO₃ is discussed.

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(10\bar10) cleavage faces of apatite were etched in citric acid and pits with and without trails were observed. The formation of the trails was studied by successively etching the same regions. Matched cleavage faces were simultaneously etched and the etch patterns were critically compared. A method is suggested for distinguishing etch pits nucleated at dislocations from those nucleated at fission tracks.

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The procedure which is utilized to derive the lattice constants of unknown substance from its powder X-ray diffraction data is described in the present paper. The essential point of the procedure is based on the probability which can be treated most readily by an electronic computer. Separate programs have been prepared for each of orthorhombic, monoclinic and triclinic systems. They have been tested with some of the powder diffraction data, which are already indexed. Both lattice constants and index assignment have been proved to be derived reliably in many cases, though depending on the quality of given diffraction data.

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The effect of the inelastic scattering by Bremsstrahlung is calculated between 10 KeV and 2000 KeV of the energy of the incident beam. The absolute value and the β(=v⁄c)-dependence of μ₀⁻¹ is evaluated numerically, and it is shown that the effect considered here is much small as compared with one of the electronic excitation.

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A possibility of observing “helicon third harmonic generation” under a phase-matched (or index-matched) condition in the submillimeter or far infrared regime is discussed. The matching condition may largely be controlled by varying an external magnetic field, and for electrons and holes in a nearly isotropic band with a small cubic anisotropy an appreciable enhancement of the power generation can be expected at ω_c=4ω, where ω_c is the cyclotron frequency and ω the frequency of the incident laser beam.

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The thermal activation energy of the electrical conduction in the polyacetylene powder was measured as a function of pressure in the temperature range from room to liquid nitrogen temperature.
The thermal activation energy of 0.27 eV at atmospheric pressure decreased to 0.17 eV at 100 kbar. Contrary to the expectation, the pre-exponential factor of the conductivity did not change at all. These results suggest that for this material the energy gap changes with pressure, while the probability of the carrier transfer between molecules does not change with the pressure.

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Reflection spectra of anthracene are analysed by Kramers-Kronig method in the wavelength region from 192 to 600 mμ. The oscillator strength of the first electronic transition A_1g→B_2u is obtained with Lorentz field correction. The oscillator strength for individual vibronic band at room temperature is in excellent agreement with that obtained in the solution spectrum. The total oscillator strength f_a+f_b is 0.100 and 0.107 at room and at liquid nitrogen temperatures respectively. The quantity of the ratio of the oscillator strength as well as the absolute value of the oscillator strength is discussed in connection with the ratio of absorption intensities. Result suggests that the first vibronic band involves a contribution which arises from a thermally induced transition.
Lorentz field in the anthracene crystal shows large anisotropy with respect to the direction of electric field applied. The oscillator strength obtained by simplified method is compared with that reported by several investigators.

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Proton and deuteron magnetic resonance have been studied at different temperatures in partially deuterated glycine and its addition compounds. The results quantitatively confirm the zwitter ion nature of glycine. The linewidth transitions in G₃H₂SO₄ and G₂HNO₃ indicate the presence of two kinds of NH₃ groups, one reorienting fast and the other slow.

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An extended version of the method of the quasi-grand partition function is presented to take into account intra- and inter-molecular interactions. This method is applied to synthetic polynucleotides, in particular to the melting transition of dAT alternating copolymer in which intra-chain folding plays an important role besides inter-chain folding. The equilibrium between single stranded and double stranded molecules in dilute solution is discussed and it is found that the major part of the alternating copolymers are single stranded when the degree of polymerization is sufficiently large. The maximum slope of the transition curve is calculated to estimate the stacking free energy which is found to be about 5.6 kcal. per mole of base pairs.

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An electron motion in a plasma subject to perpendicular electric and magnetic fields is examined by using the Boltzmann equation. The Fokker-Planck type expression for the Lorentz gas is employed for the collision term in the Boltzmann equation. The analysis is limited to an initial motion of electrons which behave under the week effect of collisions as well as the strong effect by the external electromagnetic field. Collisions between electrons and ions cause an decrease in the electron drift speed and induce electric current along the electric field.

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Parametric excitations of the ion plasma oscillations are investigated in the mercury vapour plasma. The ion plasma oscillation is excited by the pumping oscillation at 2f_pi and 2⁄3f_pi, where f_pi is the ion plasma frequency. The simultaneous parametric excitation of the ion plasma oscillation and low frequency oscillations, whose frequencies are given by f₀±f_pi where f₀ is the pumping frequency, is also studied experimentally.

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The effects of magnetic field and pressure on the radial distribution of plasma density are investigated experimentally for an energetic arc of 10¹⁴ cm⁻³ density and 2×10⁵°K temperature in relation to the diffusion phenomena of plasma. Experiments are made in argon at pressures ranging from 3×10⁻² to 3×10⁻⁵ torr and 1000∼4000 gauss of the magnetic field strength. Classical and Bohm type’s diffusion coefficients were examined for two different states of plasma: One is with low ionization degree (<35%) and the other nearly fully ionized (>98%). The experimental results show that the e-folding length of the exponentially varying density-profile is inversely proportional to the magnetic field strength at 3×10⁻³ torr pressure, whereas to the square root of the strength at 3×10⁻⁵ torr pressure. This suggests that some types of turbulence would be produced in the fully ionized plasma of energetic arc.

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An expression of the induced drag due to stream wise gasp is obtained. Contribution of the wing edge singularities to the reciprocal theorem is investigated. Some formulas for the combined flow require no inclusion of the edge-force terms, so that they are useful in some theoretical works.

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The non-linear stability of the flow of a liquid layer down an inclined plane is studied, taking into account the surface tension and the Reynolds stress due to the first periodic disturbance. The wave number and the wave amplitude of the new laminar flow are obtained as function of the Reynolds number.

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