Piezoelectric Properties of Ca 3 NbGa 3 Si 2 O 14 Single Crystal

Langasite-type single crystal Ca 3 NbGa 3 Si 2 O 14 (CNGS) was grown by the Czochralski technique. Dielectric, elastic and piezoelectric constants of CNGS were measured by the resonance-antiresonance method. At room temperature, dielectric constants ε 11 T /ε 0 and ε 33 T /ε 0 were 17.8 and 27.9, respectively. Electromechanical coupling coefficients k 12 , k 25 and k 26 were also determined as 10.9, 17.3 and 11.9%, respectively. The measurements were carried out in a temperature range from -30 to 80°C. Temperature coefficients of the dielectric, elastic and piezoelectric constants were obtained. The line-focus-beam and plane-wave ultrasonic material characterization system was employed for measuring bulk acoustic velocities, and longitudinal and transverse wave velocities of 7408.4 m/s and 3136.2 m/s, respectively, in the c -direction uncoupled with piezoelectricity at 23°C were obtained. This was in good agreement with the results determined by the resonance-antiresonance method. The density of CNGS was 4125 kg/m 3 . All the parameters of the CNGS crystal for bulk and surface acoustic wave applications were determined in this research.