Elastic and inelastic scattering of 28.5 MeV alpha particles by Ni⁶⁰, Ni⁵⁸, Ti⁴⁸, Co⁵⁹ and Al²⁷ has been studied. The angular distributions of the prominent group from the 2⁺ first excited state and the 3⁻ “anomalous” group for even nuclei were fitted by calculations based on Blair model. The angular distributions of the 4⁺ groups near 2.5 MeV in Ni⁶⁰, near 2.5 MeV in Ni⁵⁸ and near 3.3 MeV in Ti⁴⁸ were found to have intermediate phase between the corresponding elastic distribution and the corresponding first 2⁺ inelastic distribution. On the other hand, the angular distributions of the 2⁺ groups near 3.1 MeV in Ni⁶⁰, near 3.0 MeV in Ni⁵⁸ and near 2.4 MeV in Ti⁴⁸ were found to be almost exactly out of phase with the corresponding elastic distributions.
Large cross sections of the inelastic alpha scattering to the 2.21– and 3.0–MeV states in Al²⁷ suggest that these states are the members of a K^π=5⁄2⁺ rotational band based on the ground state.

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The electrical resistivity, optical transmission, effects of chemical etching, Hall effect, thermoelectric force and electron spin resonance have been studied on single crystals of BaTiO₃ reduced for five hours at temperatures from 400 to 1000°C in a hydrogen atmosphere. The reduction treatment causes a lowering of the resistivity, and enhancement of the infrared absorption centered at 2.3μ and a visible absorption near the optical absorption edge. The single crystals are not always reduced homogeneously. The resistivity of a homogeneously reduced crystal changes abruptly at the three transition temperatures. The sign of the Hall coefficient and the thermoelectric power indicates that the charge carriers in the reduced crystals are electrons. On the basis of the results obtained, a tentative model is proposed for defects in the reduced single crystal.

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The interactions between several impurities and Frenkel defects introduced by γ-ray and neutron irradiation at room temperature in Si crystals were investigated mainly by Hall effect measurements. The following conclusions have been obtained: (1) Annealing behavior of A center is different from sample to sample. (2) Annealing temperature of A center increases remarkably with increasing A center density or irradiation dosage. (3) Several deep levels, for example, E_c–0.4 ev center are also produced by γ-ray and neutron irradiation. Their annealing behavior is considerably different from that of A center. (4) The radiation effect and annealing behavior of lifetime show similar features to those of the deep levels stated above. (5) Ni diffused in Si crystals acts as acceptor level (E_c–0.34 ev) and causes negative annealing of deep levels.

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Origin of electric field gradient due to strains in alkali halide crystals is unravelled from the experimental determination of gradient-elastic tensors. Tensors for ²³Na, ³⁵Cl, ⁸¹Br and ¹²⁷I in a series of crystals are determined from the quadrupolar broadening of resonance lines due to solute ions, using lattice distortion derived from lattice parameter changes.
Results are interpreted by the theory which takes account of the contribution from valence electrons, besides point charge arrays, and gives an expression of a gradient-elastic tensor in terms of an anti-shielding factor, overlap integrals and a degree of covalency.
An excellent agreement is found between the theoretical and experimental tensor values for ²³Na in NaCl, for which both theory and experiment are least ambiguous. For other crystals, a degree of covalency is tentatively estimated, with reasonable results.

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Electron spin resonance of Cr²⁺ in cadmium sulfide single crystals has been studied at liquid helium temperature range and X-band. The observed spectra consist of six main lines having anisotropic g-values. They are interpreted in terms of a Jahn-Teller distortion of Cr²⁺ ion in directions nearly bisecting the lines to the nearest sulfur neighbors. There are such six directions in the crystal. The effective spin Hamiltonian appropriate to explain the results obtained at 1.4°K is
\mathscrH_eff=g′_\varparallelβH_zS_z+ΔS_x,
where g′_\varparallel=7.75±0.03, g′_⊥∼0, Δ=0.150±0.002 cm⁻¹, and S=1⁄2, and the z-axis makes an angle of 57°45′ with the c-axis in the (11\bar20) plane or its equivalent planes, which coincides with the direction along which the Jahn-Teller distortion takes place. Resolved hyperfine interaction is observed with Cd¹¹¹ and Cd¹¹³, whose hyperfine splitting constant is (2.1±0.1)×10⁻³cm⁻¹. The results are compared with the work of Estle, Walters, and deWit. A photosensitive spin resonance line has been observed at 1.7°K under visible light illumination.

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The wave-number-dependent dielectric function is calculated for crystalline KCl, on the basis of the expressions derived in a previous paper. The value, 2.383, is obtained for the static dielectric constant in long wave length limit, which is to be compared with the observed optical dielectric constant ε_∞=2.13. The contribution from the Umklapp terms has turned out to be rather small. An approximate analytical expression is presented for the screened Coulomb potential in KCl crystal.

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Under the assumption that stress is expressible as a polynomial of elastic strain and actual strain rate, a rheological equation optimum to describe the behaviour of viscoelastic liquid is derived as follows:
τ=(p+α₀)1+α₁ε+α₂f+α₃ε²+α₄f²+α₅(εf+fε)+α₆(ε²f+fε²)
+α₇(εf²+f²ε)+α₈(ε²f²+f²ε²)
where p is a hydrostatic pressure, τ, 1, ε and f are stress tensor, metric tensor, strain tensor and strain rate tensor, respectively, and α₀, α₁···α₈ are polynomials of ten invariants of elastic strain and actual strain rate. Assuming that in simple shearing flow the stress tensor has the same principal axes to the elastic strain tensor and two normal stresses in the direction perpendicular to the stream are equal to each other, the above equation is reduced to
τ^ij=(−p+α₀)G^ij+α₁ε^ij+α₇(ε_αⁱf_β^αf^βj+f_αⁱf_β^αε^βj)
Applications of the theory to simple shearing flow and steady flow through pipe are considered, with satisfactory results.

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The microwave radiations from a dc discharge plasma in a magnetic field were studied. The experimental results showed that the resonant radiations of the extraordinary wave, propagating perpendicular to a magnetic field, were observed not only at ω=(ω_p²+ω_b²)^1⁄2, but also near the cyclotron harmonics. On the other hand, it was shown that the dispersion relation for the plasma type oscillations derived by Bernstein had a harmonic structure: In our experimental condition this dispersion curve was divided into many branches, each of which approached asymptotically to the curves given by ω²=ω_p²+ω_b² and by ω=nω_b(n being an integer). The resonant radiation detected was interpreted as the plasma type radiation, above mentioned. The gaps in the radiation spectrum at the cyclotron harmonics were not measured in our discharge plasmas. Further, the number of the successive harmonics in a radiation increased with decreasing a gas pressure, independently of a kind of gas used.

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The microwave radiation from a dc discharge plasma in a magnetic field was studied. The experimental results showed that the resonant radiations of the ordinary wave, propagating perpendicular to a magnetic field, were observed near the electron cyclotron harmonics. The number of the successive harmonics increased with decreasing the gas pressure, independently of the kind of gas used. The characteristics of these radiations were very similiar to those of the extraordinary wave. Such cyclotron harmonics were discussed by the dispersion relation.

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The interaction of a plasma stream with a three dimentional dipole has been experimentally investigated. The time exposure photographs and magnetic probe measurement showed the formation of a magnetic cavity just as theoretically predicted.

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Page Column Line
1804 right 5 from the top J. Phys. Soc. Japan in press.
should be read as
Japan. J. appl. Phys. 2 (1963) 386.

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Figures 7 and 8 should be exchanged.

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