New results on high perfection langasite crystals: studies of crystalline defects and mode shapes

摘要: Langasite (LGS: La/sub 3/Ga/sub 5/SiO/sub 14/) is a new piezoelectric material obtained by the Czochralski method. In this paper we present results on samples which are more representative of crystalline quality achieved with material. Observations using X-ray transmission topography have permitted verification different origins and to analyse nature their defects. Vibration modes types devices made LGS been studied topography. This study was essentially concerned plane or plano-convex resonators. has interesting properties among them compensated cuts large coupling coefficient very reduced angular sensitivity.