Na2CoGeO4 single crystal growth and study of their piezoelectric and elastic properties

Abstract Sodium cobalt germanate Na 2 CoGeO 4 single crystals were grown by different techniques under hydrothermal conditions. Peizoelectric, elastic and dialectric properties of these crystals were investigated. The sound velocities varied from 4.4 to 5.8 × 10 5 cm/sec for longitudinal waves and from 2.1 to 3.2 × 10 5 cm/sec for shear waves. Maximal electromechanical coupling factor was 25%. All independent components of tensors of piezoelectric, elastic and dielectric constants, and elastic and piezoelectric modules were determined.