New piezoelectric crystal: Synthetic fresnoite (Ba2Si2TiO8)

Abstract

A fresnoite (Ba2Si2TiO8) single crystal was grown from the melt by the Czochralski method. Synthetic fresnoite has an electromechanical coupling factor in the thickness shear mode of k15=0.28, and a resonance-frequency temperature coefficient in this mode of Tfr=−33 ppm/°C. Fresnoite is considered to be superior to Ba2Ge2TiO8 for various piezoelectric applications because of the absence of microtwins observed in Ba2Ge2TiO8.