Growth habits and high temperature properties of langatate single crystal

This paper shows that high quality LGT single crystals with the size of 2" were grown by Czochralski method along different direction. The facets and the solid-liquid interface during crystal growth process were investigated, and flat interface was obtained by adjusting the rotation rate. X-cut wafers were used to test frequency constant, resistivity, piezoelectric constant and crystalline perfection. The results indicate that frequency constant value was around 2.77 MHz·mm with a vitiation of 0.2% along the whole crystal; the resistivity of top part and bottom part both higher than 10⁷ Ohm·cm at 500 °C; piezoelectric coefficient (d₁₁) was 7.0 pC/N; diffraction angle is 22.3228° and the full width at half maximum (fwhm) value is 33.5 arcsec. In all, the LGT crystal was in high quality and high homogeneous, can be used to high temperature acoustic wave devices and sensors in applications.