Growth and Characterization of Novel (Sr 0.5 Ca 0.5 ) 3 Ta(Ga 0.5 Al 0.5 ) 3 Si 2 O 14 High Temperature Piezoelectric Crystal

Author of the article:ZHAO Guiyuan 1 , LIU Lei 1 , YIN Fangyi 1 , ZHU Menghua 2 , FU Xiuwei 1 (1. State Key Laboratory of

Author's Workplace：1. State Key Laboratory of Crystal Materials, Shandong University, Ji'nan 250100, China; 2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China

Key Words： langasite; high temperature piezoelectric; piezoelectric coefficient; Czochralski method; crystal growth

Abstract： Langasite crystals are considered the preferred materials for high-temperature sensors due to their high resistivity and excellent piezoelectric properties. In this paper, a novel (Sr 0.5 Ca 0.5 ) 3 Ta(Ga 0.5 Al 0.5 ) 3 Si 2 O 14 (SCTGAS) high temperature piezoelectric crystal was successfully grown by the Czochralski method for the first time. The effects of ion substitution on crystal growth and electrical properties were then studied. The as-grown SCTGAS crystal is colorless with a plate growth morphology, having high transmittance in the visible light band. The crystal shows a high resistivity, with a value over 10 9 Ω · cm at 450 ℃. In addition, Sr substitution can significantly enhance the piezoelectric coefficient d 11 , which reaches 5.55 pC/Nat 550 ℃. Therefore, the SCTGAS single crystal is very promising for high-temperature piezoelectric sensors. Key words ： langasite; high temperature piezoelectric; piezoelectric coefficient; Czochralski method; crystal growth.