We have confirmed a high dielectric constant after poling ε33 T/ε0 of 7700 and piezoelectric constant d 33 = 2250 pC/N, which are 40% larger than those of the initial sample, for a lead magnesium niobate–lead titanate 0.72 Pb(Mg1/3Nb2/3)O3–0.28 PbTiO3 single crystal plate with a manganese oxide/gold (Au) composite electrode. The increased ε33 T/ε0 and d 33 may be attributable to the smaller domains realized by fine patterning semiconductor manganese oxide and conductive Au composite electrodes on the single crystal plate. The use of a semiconductor/conductor composite electrode is an effective method of improving the properties of piezoelectric single-crystal transducers.

The epitaxial growth of vanadyl phthalocyanine (VOPc) on KBr-NaBr mixed-crystal substrates was examined. The experimental results indicate that the orientation and morphology of the film are primarily affected by the lattice constants of the substrates, but not by differences in the substituted components, e.g., alkali or halogen. The VOPc island crystal domains grew even on large-mismfit NaBr substrates. Their characteristic shape and the possible growth process are also discussed.

The mechanical properties of high-temperature-vulcanization silicone (Q) rubber doped with zinc oxide (ZnO) fine powders have been investigated to develop an acoustic lens material with high reliability. The ZnO-doped Q rubber with an acoustic impedance (Z ) of 1:46 Â 10 6 kgÁm À2 Ás À1 showed a tear strength of 43 N/mm and an elongation of 560%. These mechanical property values were about 3 times higher than those of conventional acoustic Q lens materials. The ZnO-doped Q rubbers also showed a lower abrasion loss. These superior characteristics are attributable to the microstructure with fewer origins of breaks; few pores and spherical fine ZnO powder. The high mechanical properties of ZnO-doped Q rubber acoustic lenses enable higher performance during long-life and safe operation during diagnosis using medical array probe applications.