The NMR spectra of ¹⁵¹Eu and ¹⁵³Eu nuclei with the nuclear spin I=5⁄2 were observed in ferromagnetic EuS using a single-crystal sphere by the cw method in fields up to 21 kOe below 4.2 K. In fields above magnetic saturation the ¹⁵³Eu spectrum consists of quadrupole-split five lines whose relative intensities depend on field direction. The central-line frequency which gives a hyperfine field at nuclei exhibits a small anisotropy in good agreement with the previous results, but the frequency separation Δν_q between the quadrupole multiplets is isotropic, which is determined to be 0.358±0.005 MHz at 4.2 K. The temperature dependence of Δν_q is rapid compared with that of the Eu magnetic moment. A linear extrapolation to absolute zero gives a value of Δν_q=0.422±0.005 MHz which yields a quadrupole coupling of e²qQ⁄h=2.81±0.03 MHz. The ¹⁵¹Eu spectrum is a single line even in magnetic fields.

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The ⁵⁹Co NMR from magnetic domains in a hcp cobalt metal was studied using a single crystal by the steady-state method over a temperature range of 4.2–516 K in zero external magnetic field. The resonance frequency ν_T of the central line of the quadrupole-split NMR spectrum at temperature T was measured as a function of T. ν_4.2 was determined to be 219.78±0.03 MHz in good agreement with the previous result. The reduced frequency (ν_4.2−ν_T)⁄ν_4.2 was compared with the reduced magnetization (M_4.2−M_T)⁄M_4.2. Both were found to agree well below about 60 K, but to show a marked discrepancy above this temperaure, suggesting an anomaly at about 60 K in the magnetic state of cobalt metal. Below 40 K, the temperature dependence of (ν_4.2−ν_T)⁄ν_4.2 was analysed based on a simple spin-wave theory. The analysis yields the spin-wave stiffness constant D=337±14 meV Ų which is much smaller than that derived from neutron scattering.

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Dielectric and conducting properties of synthesized single crystals of magnetite have been studied below the Verwey point T_v=122 K. A wide frequency range of ac field and dc field have been adopted for the measurements. A magnetic field cooling treatment has been used for controlling the alignment of c-axis (magnetic easy axis below T_v). The properties along the c-axis and perpendicular to it show a considerable contrast. Also, a conspicuous dielectric relaxation has been found below 70 K. The low temperature ac conductivity fits in with the relation σ_ac∝ω^s (s∼0.7 at 6.8 K), consistent with the well known hopping conduction mechanism. The dc conductivity is well represented by σ_c⁄⁄∝exp (−74.5T^−1⁄4), and σ_c⊥∝exp (−55.0T^−1⁄4), suggesting that the mechanism of variable range hopping of charge carriers predominates.

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Optical properties of poly(N-vinylcarbazole) films and solutions are investigated by the site-selective excitation method. The localized excitons induced by the disorder are found to be generated below the energy of the exciton absorption band. The hopping of the localized exciton is found to play an important role in the dynamical process. In the films, the localized excitons hop well into the excimer-forming sites, and are observed as the excimer fluorescence. In the solutions, a fluorescence band due to the localized excitons appears in addition to the excimer fluorescence. This appearance is explained by a smaller efficiency of the exciton hopping into the excimer-forming sites than that in the film.

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Optical absorption spectra of Cu²⁺ ions doped in ND₄Cl(basic) and NH₄Cl(acidic) crystals have been studied in the temperature range from 300 K to 173 K. An abrupt red shift of the position of the band maxima assigned to the transition ²A_1g→²E_g is observed at 248 K in ND₄Cl and at 241 K in NH₄Cl crystals and this is attributed to the ordering of coordinated molecules ND₃ and H₂O respectively. The results are compared with Cu²⁺:NH₄Cl(basic) and Cu²⁺:NH₄Br(acidic) crystals.

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In this work, iodine L₁-XANES of (CHI_0.02)_x excited by two linearly polarized X-ray are analyzed by use of the short-range order full multiple scattering calculations. The XANES analysis for E⊥c polarization gives us the information on the I-C correlation. One useful information obtained here is that the nearest I-C distance is longer than the sum of the van der Waals radii of I and C. This result can explain the increase of the anisotropy of the electric conductivity with iodine doping. Our XANES analyses also confirm the charge distribution on polyanions I₃⁻ and I₅⁻ determined by Mössbauer spectroscopy.

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In this work, we have analysed the Br K-edge XANES of (CHBr_y)_x excited by polarized X-ray in ⁄⁄c and ⊥c directions for three different doping region. In the low doping region it is proved that mono-anions exist, and the information about the charge distribution on carbon chains around the mono-anions is obtained. The maximal amplitude of the charge density is larger than 0.4. In the intermediate doping region (y=0.0145), the XANES analyses also confirm the model previously proposed by Oyanagi et al., in which polyanions Br₃⁻ and covalently bonded bromine atoms coexist. From the analysis of E⁄⁄c XANES, it is concluded that Br₃⁻ has larger polarization approximately shown by Br^−0.6Br^−0.2Br^−0.6 than I₃⁻ by I^−0.5I^0.0I^−0.5. In the high doping region, there are many possible models more than 10⁶. In this case the detailed analyses would be impossible.

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The Kerr constants in C₆H₆ and C₆H₅NO₂ are discussed by means of the statistical mechanics of Maxwell-Boltzmann’s distribution of the molecules under the biasing field. The anisotropic electronic polarizabilities are obtained as α₁=12.06 (ų) (parallel to C₆H₆ plane) and α₂=7.143 (ų) (perpendicular to C₆H₆ plane) for the Kerr constant 6.0×10⁻¹⁸ in C₆H₆, and also α₃=13.644 (ų) (parallel to the polar axis) and α₁+α₂=26.50 (ų) for the Kerr constant 269×10⁻⁷ in C₆H₅NO₂.

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A new theoretical scheme is proposed for polaritons in bounded media, from a semi-infinite system to a quantum well. For each specific model, this theory allows a direct calculation of the electric field E(r) of polaritons without referring to any additional boundary condition (ABC). For a thick enough sample, bulk polaritons emerge automatically in the expression of E(r). Applications are shown in two simple cases; (i) a single quantum well, and (ii) a semi-infinite medium with simple exciton wave functions.

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Viscosity and density data for aluminium ammonium sulphate and potassium aluminium sulphate in tert-butyl alcohol-water (tert. BuOH–H₂O) solutions [5, 10, 15 and 20 wt%] at different concentrations and temperatures are presented. The viscosity data have been analysed by means of Jones-Dole equation. The activation parameters of viscous flow were obtained by means of the application of transition state theory in order to estimate the mechanism of the viscous flow. The density data have been analysed by using the Masson’s equation. The limiting apparent molar volume φ_v⁰, and the experimental slope S_v, have been interpreted in terms of solute-solvent and solute-solute interactions, respectively. The φ_v⁰ values vary with temperature as a power series of temperature. Structure making/breaking capacities of the multicharged electrolytes have also been inferred from the sign of (∂²φ_v⁰⁄∂T²). Both the electrolytes behave as structure makers/promotors.

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