[19p-H112-1~15] 15.1 Bulk crystal growth

▲ [19p-H112-9] Electrical resistivity, dielectric and piezoelectric properties of Ca₃TaGa_3-xAl_xSi₂O₁₄ (CTGAS) single crystals as a function of Al content

〇(D)Xiuwei Fu^1,2, Encarnacion G. Villora¹, Yuuki Kitanaka³, Yuji Noguchi³, Masaru Miyayama³, Kiyoshi Shimamura^1,2, Naoki Ohashi^1,4 (1.NIMS, 2.Waseda Uni., 3.Uni. Tokyo, 4.Tokyo Inst. Tech.)

Keywords:Langasite,High temperature sensors

Piezoelectric langasite single crystals are attracting much attention for high temperature (HT) sensor applications. These compounds do not present any phase transition up to their melting points (1300-1500^oC), exhibit good piezoelectric properties, are non-pyroelectric, and can be grown by the Czochralski (Cz) technique. Among the langasite family, Ca₃TaGa₃Si₂O₁₄ (CTGS) and Ca₃TaAl₃Si₂O₁₄ (CTAS) single crystals are particularly promising for HT sensor applications due to their relatively high resistivity. So far, the growth of mixed crystals Ca₃TaGa_3-xAl_xSi₂O₁₄ (CTGAS) has been reported to be difficult, and thus the influence of Al content on the electrical and piezoelectric properties hasn’t been investigated systematically yet. In this work, transparent CTGAS single crystals (x=0~3) are successfully grown under same nominal conditions. Their properties are investigated in detailed.