X-ray topography of piezoelectric La(3)Ta(14)Ga(5.5)O(14) crystal grown by Czochralski Method.

We performed synchrotron X-ray topography on a La(3)Ta0(0.5)Ga (5.5)O(14) (LTG) crystal grown by the Czochralski method. Since a synchrotron X-ray source can provide high-energy X-rays, one can detect bulk structures by X-ray topography. LTG is one of the most attractive piezoelectric crystals along with La(3)Ga(5)SiO(14) (LGS) because of its excellent acoustic properties (temperature compensation of acoustic losses). Since LTG single crystals can be grown from a stoichiometric melt, it was expected that single crystals with better quality than the LGS crystal, which cannot be grown from a stoichiometric system but only from a congruent melt, can be obtained. However, 60 keV X-ray topography revealed that the LTG crystal quality was not as high as the LGS crystal quality. The crystal quality of the central region was lower than that of the surrounding region.

Phase transition characteristics in PbZrO(3) based PZT-PZN solid solution ceramics.

The ternary oxide solution of lead zirconate titanate (PZT) with a complex perovskite oxide Pb(Zn(1/3)Nb(2/3))O(3 ), (PZN), a composition that is near that of PbZrO(3), was prepared, and its phase transition behavior was investigated. An extension of the ferroelectric phase by the addition of PZN and a change of the transition between two ferroelectric phases from a first-order to a second-order nature are described.

Low-loss ZnO optical waveguides for SAW-AO applications.

Acoustooptic Bragg deflectors (ABDs) with high diffraction efficiencies were fabricated using ZnO thin films deposited on sapphire, glass, and Si substrates by an RF magnetron sputtering system. Optical waveguide losses of the ZnO films were about 0.5 dBcm(-1). Diffraction efficiencies of 95 and 98% for the TE(0) mode beam (at 632.8 nm) were accomplished by acoustic powers of 90 mW in a ZnO film on glass and 80 mW in a ZnO film on Si, respectively. The diffraction efficiencies of the ABD using a ZnO film on sapphire with interdigital transducers of different Q values and with the surface-acoustic-wave propagating along and perpendicular to the c -axis of the ZnO film were also determined.