Temperature-dependent behaviours of electro-elastic constants for the Bi2ZnB2O7 piezoelectric crystal

Abstract

The bismuth-based borate Bi₂ZnB₂O₇ (BZBO) crystal is a multi-functional material with potential non-linear optical and piezoelectric properties. In this study, the temperature-dependent behaviours of the dielectric permittivities, resonant frequencies, elastic compliances and piezoelectric coefficients for Bi₂ZnB₂O₇ crystals were studied over the temperature range of −150–150 °C. The Bi₂ZnB₂O₇ crystals were found to present minimal dielectric permittivity variations (<10%) and low dielectric losses (<1%). The temperature coefficients of the elastic compliances were found to be in the order of 0.98 × 10⁻⁴–1.17 × 10⁻⁴/°C, showing good temperature stability. The resonant frequencies decreased with increasing temperature, and the variations were all in −2%. The temperature dependence of the piezoelectric coefficients for the Bi₂ZnB₂O₇ crystals was studied, and the piezoelectric coefficients showed different trends as a function of temperature, whereby the first order of TCPs were found to be in the order of −5.10 × 10⁻⁴–3.88 × 10⁻⁴/°C. In addition, the maximum piezoelectric rotated crystal cuts for the Bi₂ZnB₂O₇ crystals were (YXt)/59° and (YXt)/146° for longitudinal and thickness shear vibration modes, respectively.