Electroacoustical constants and Rayleigh surface acoustic wave propagation characteristics of calcium aluminate silicate Ca2Al2SiO7 single crystals

Electroacoustical constants (epsilon(T)(ij), s(ij)(E), and d(ij)) of calcium aluminate silicate Ca2Al2SiO7 piezoelectric single crystals, which have the tetragonal structure with the point group 42m, were evaluated. The normalized first-order temperature coefficients of all the constants were determined between -30 and 120 degrees C at 10 kHz frequency, e.g., for epsilon(T)(11) and epsilon(T)(33) were 69.3 and 87.6, and for d(14) and d(36) were -338.4 and 552.4 ppm/degrees C, respectively. The Rayleigh surface acoustic wave (SAW) velocities for the fundamental X- and Z-cuts of the crystals were theoretically calculated. The results were supported by the SAW velocities measured for the Z-cut of the crystal, proving the accuracy of the electroacoustic constants determined in this study. (C) 2018 The Japan Society of Applied Physics