| This paper reports on the langatate (LGT) elastic constants and their temperature coefficients measured from room temperature (25°C) to 1100°C using resonant ultrasound spectroscopy (RUS). The constants were extracted by iteratively fitting the resonant peaks with those calculated by Lagrangian mechanics at each temperature where the RUS measurements were taken. In addition, the RUS technique was used to extract the elastic and piezoelectric constants in the 25°C to 120°C temperature range. The extraction of LGT elastic constants up to 1100°C presented in this paper represents a critical step towards the design and fabrication of LGT acoustic wave devices for high temperature and harsh environment applications. |