Langatate temperature-compensated BAW orientations identified using high-temperature constants

LGT BAW orientations are investigated up to 900°C for temperature-compensated orientations targeting harsh-environment applications. The study utilizes recently published LGT elastic, piezoelectric, and dielectric constants extracted by the authors using resonant ultrasound spectroscopy (RUS) up to 900°C based on the resonances of bulk crystal samples. Temperature-compensated LGT BAW orientations have been identified for operation at high temperatures. The orientations disclosed in this work have turnover temperatures between 100°C and 550°C for the one quasi-shear mode and up to 150°C for the other quasi-shear mode. Additionally, orientations were identified with pure transverse-shear modes that are selectively excitable and have temperature compensation up to 550°C. These orientations can be readily applied for both frequency control and sensor applications in harsh environments.