A Review on High Temperature Piezoelectric Crystal La₃Ga₅SiO₁₄ for Sensor Applications

In this review article, we have investigated the credibility and suitability of the lanthanum gallium silicate (La₃Ga₅SiO₁₄, LGS) crystals in the application of high-temperature sensing. All the basic properties of the langasite family piezoelectric crystals, such as elastic properties, are taken into consideration and discussed. The crosstalk effects between different vibration modes of LGS crystal are investigated to optimize the crystal cuts. Thereafter, dependences of properties, such as electroelastic properties, resistivity, and electromechanical coupling coefficients of langasite family crystals on higher temperatures, are discussed. Finally, thermal-related properties of langasite family crystals, such as specific heat as well as thermal expansion coefficients, are studied for higher temperature ranges and a comparison with other piezoelectric crystals has also been presented.