Unusual pyroelectric and piezoelectric properties of fresnoite (Ba2TiSi2O8) single crystal and polar glass-ceramics

Abstract

The dielectric, piezoelectric and pyroelectric properties of fresnoite (Ba2TiSi2Os) single crystal and polar glass-ceramics were studied in the temperature range - 150 to 200°C. The sign of pyroelectric coefficient is positive at room temperature and becomes negative at 190°C. The dielectric constant, pyroelectric coefficient and planar coupling coefficient show a maximum value at 160°C and the frequency constant shows a minimum at the same temperature. The probable reasons for the anomaly in these properties are discussed.