Annealing Effects for Ca₃NbGa₃Si₂O₁₄ Piezoelectric Single Crystals Grown by Micro-Pulling-Down Method

Abstract

The langasite-type Ca₃NbGa₃Si₂O₁₄ [CNGS] piezoelectric crystals grown in Air and Ar were annealed under various temperatures and atmospheres and the effects of annealing on various properties were investigated. The absorption peaks around 360 and 500 nm of CNGS crystals grown in Air decreased by the annealing at 1300°C in Ar. On the other hand, the annealing at 1300°C in Air decreased transmittance in the range from 300 to 500 nm for the CNGS crystal grown in Ar. The results suggest that the absorptions around 350 and 500 nm originate from the excess oxygen and the post-annealing can control the oxygen content in the crystals.

Keywords:

• Piezoelectric crystal
• langasite
• annealing effect
• single crystal

Acknowledgments

This work was partially supported by Ministry of Education, Culture, Sports, Science and Technology of Japanese government, Grant-in-Aid for Young Scientists (B), 23750234.