Dielectric, elastic and piezoelectric properties of SrLaGa3O7 and BaLaGa3O7 crystals with Melilite structure
A full matrix of electromechanical properties of Melilite SrLaGa3O7 and BaLaGa3O7 crystals was evaluated by the impedance method, with minimal variations being observed for the two crystals. The , d14 and k14 were determined to be 13.6, 9.4-9.5 pC/N and 17.1-17.4%, respectively. The relationship between electromechanical properties and microstructures was established to explain the elastic relationship, and piezoelectric origin. The optimized electromechanical properties were investigated in double rotated coordinate. The high resistivity (∼108 Ohm·cm), high thermal stability of elastic constants (with variations of <10%) and piezoelectric properties (with minimal variation of 8%) over the temperature range of 25-500 °C, making SrLaGa3O7 an attractive candidate for sensing applications at elevated temperatures.