Characterization of piezoelectric materials : old and new crystals

Abstract

Some piezoelectric materials obtained by the hydrothermal growth method or by the Czochralsky growth method are studied. Their crystalline quality has been determined by X-ray topography using the synchrotron radiation at LURE (Orsay, France). In the case of the gallium phosphate the growth process with berlinite seeds has been studied by the section topography method. The use of berlinite seeds seems to be a good process to obtained rapidly large good seeds of gallium phosphate and therefore large crystals. Some results concerning the vibration modes and in some cases the interactions between the defects and the acoustic vibrations are presented