Mechanism of Piezoelectricity for Langasite Based on the Framework Crystal Structure

Piezoelectric langasite crystals have superior properties such as high temperature performance and high qualityQ and can be applied in combustion pressure sensors and surface acoustic wave (SAW) filters. Crystal growth,crystal structure and properties of langasite group are reviewed, and the mechanism of piezoelectricity of langasiteis presented based on the crystal structure and deformation under high pressure. Finally, for the discovery of newpiezoelectric materials, this paper presents the role of the framework, and recommends the search of frameworkcrystal structure, because the characteristic of the mechanism exists on the framework of the crystal structure.