Higher harmonics of complex susceptibility were measured for single-crystal YBa2Cu3O7-x, bulk specimen and thin films. For the bulk specimen, any higher harmonics were not observed. This result is consistent with the Maxwell and Strongin model. In contrast with this, for the thin film specimen placed in transverse magnetic field, third harmonics have a finite value in the transition region. This suggests the existence of nonlinear flux motion going into and out of the specimen.
The orientation of YBa2Cu3O7-x thin films grown on (110) planes of SrTiO3 by activated reactive evaporation was investigated by means of reflection high energy electron diffraction. The orientation of the films depended on the substrate temperature. The films with the (110) plane parallel to the substrate surface grew in the narrow range of substrate temperatures around 530°C, while the films with the (103) plane parallel to the surface grew at the temperatures above 600°C. The change of the epitaxial orientation with the substrate temperature was discussed refering the temperature dependence of the lattice mismatch between YBa2Cu3O7-x and SrTiO3.
Solubilization of milk fat globule membrane (MFGM) and its apoprotein was attempted by using the nonionic detergents such as Triton X-100, Tween 20, Nonidet P-40, Liponox NCK and Emulgen 109-P. About 40 to 60% of MFGM and 5% of its apoprotein was solubilized with the nonionic detergents alone. In these cases, selective solubilization was observed on SDS-polyacrylamide gel electrophoresis. The supplementary factors such as the presence of urea and an increase in pH were found to enhance the solubilizing ability of Triton X-100. In particular, a combination of 8 m urea with 2 ~ 5 % nonionic detergents in the presence of 0.2 % 2-mercaptoethanol accomplished complete solubilization of MFGM and its apoprotein. After complete solubilization the removal of urea by dialysis in the presence of the detergent did not cause the reaggregation of protein-detergent complexes. The biologically active components such as marker enzymes of MFGM in the completely solubilized protein fraction was denatured with urea.
Using an rf-magnetron sputtering method, highly c-axis oriented La-modifiedPb TiO3 (PLT) thin films with composition of Pb1-xLaxTi1-x/4O3, where x=0.0, 0.05, 0.10 and 0.15 have been obtained on MgO single crystal and epitaxial Pt thin film substrates under the condition of low gas pressure and low deposition rate. It was found that the significant pyroelectric currents were detected for all as-grown specimens even without poling treatment and the directions of the currents were the same in all specimens. Relative dielectric constant εr decreased, and pyroelectric coefficient γ increased with increasing degree of c-axis orientation. εr and γ became large with increase of La content in the films. Considering the figure of merit for pyroelectric infrared detection, it is concluded that PLT films with x=0.10 are good material for pyroelectric infrared detector.
Lead zirconate-titanate (PZT, PbZr x Ti 1- x O 3 , x =0.2-0.9) films with submicron thickness (600-900 nm) were prepared using an rf -magnetron sputtering technique. The crystal structure and the orientation of the films were studied as a function of the substrate temperature. The relationships between electric properties and the film compositions were elucidated. The films of x =0.90 exhibit a large remanent polarization of 46 µC/cm 2 and small coercive force of 28 kV/cm. In addition, no fatigue after >10 11 cycles under an accelerated bipolar stressing was observed.
Using an rf-magnetron sputtering method, highly c-axis-oriented La-modified PbTiO3 (PLT) thin films with compositions of Pb1−xLaxTi1−x/4O3, where x=0.05, 0.10, and 0.15, have been obtained on MgO single-crystal and epitaxial Pt thin-film substrates under conditions of low gas pressure and low deposition rate. The degree of c-axis orientation of the PLT films decreases, and the tetragonality of PLT becomes smaller with increasing La content. The Curie point of the films decreases at a rate of 18 °C/at. % of La with an increase of La content. D-E hysteresis loops were observed, and these became slim and symmetric with increasing La. It was found that significant pyroelectric currents are detected on all as-grown specimens even without a poling treatment, and the directions are the same in all specimens. Relative dielectric constant εr decreases, and pyroelectric coefficient γ increases with increasing degree of c-axis orientation. εr and γ became large with increase of La content in the films. Considering the figure of merit for pyroelectric infrared detection and the temperature coefficient of γ, it was concluded that PLT films with x=0.10 were good material for pyroelectric infrared detectors.
