| 摘要 |
PROBLEM TO BE SOLVED: To provide a lead-free piezoelectric ceramic exhibiting a large piezoelectric strain constant d33 and having high thermal resistance, which is suitable as a knock-sensor element, and to obtain a lead-free piezoelectric ceramic exhibiting a large piezoelectric strain constant d33 of >=100 pC/N and a decreasing rate D33 of the piezoelectric strain constant d33 of <=15% in absolute value when the piezoelectric ceramic is subjected to high temperature shelf test of 150 deg.C×72 h. SOLUTION: The piezoelectric ceramic contains three components of BNT bismuth sodium titanate; (Bi0.5Na0.5)TiO3}, BT (barium titanate; BaTiO3) and BKT bismuth potassium titanate; (Bi0.5K0.5)TiO3}. It is preferable that such piezoelectric ceramic contains a tetragonal perovskite-type crystal structure. |
