文摘
Single ABC3O7 crystals with the melilite structure, including SrLaGa3O7, SrGdGa3O7, and BaLaGa3O7, have been successfully grown by the Czochralski method. A complete set of room temperature elastic, dielectric, and piezoelectric constants was determined using resonance techniques and impedance analysis. Our results indicate that the crystals exhibit superior piezoelectric and elastic properties. The electrical resistivity was found to be on the order of 6 脳 1013 ohm路cm at room temperature. The dielectric permittivity 蔚11, piezoelectric constant d14, and electromechanical coupling coefficient k鈥?sub>12 were found to be on the order of 15鈥?7, 12鈥?5 pC/N, and 16鈥?9%, respectively. For an ABC3O7 group member such as SrLaGa3O7, the melting temperature was measured to be 1588 掳C, below which the crystal maintains good thermal stability. Consequently, the piezoelectric properties were studied as a function of temperature over the range of 鈭?0 to 120 掳C. The frequency vs temperature coefficient was determined to be 鈭?6 to 鈭?5 ppm/K, depending on orientation. The dielectric permittivity, piezoelectric constant, and electromechanical coupling coefficient showed good temperature stability. The absence of any phase transitions below their melting points (on the order of 1600 掳C) makes the ABC3O7 family promising candidate materials for high temperature piezoelectric applications.