| 摘要 |
PROBLEM TO BE SOLVED: To realize a high Curie point in piezoelectric ceramics containing (Bi1-aNaa)bTiO3 as a principal component and BicFeO3 as an accessory component and further containing a perovskite type crystal by regulating the molar ratio of the accessory component to the principal component within a specific range. SOLUTION: The piezoelectric ceramics contain (Bi1-aNaa)bTiO3 [(a) is 0.4-0.6; (b) is 0.95-1.05] as a principal component and BicFeO3 [(c) is 0.95-1.05] as an accessory component. The molar ratio of the accessory component to the principal component is >0 and <=0.1. The piezoelectric ceramics are preferably substantially composed of a perovskite type crystal, but need not be completely homogeneous or may contain, e.g. a heterogeneous phase. The piezoelectric ceramics most preferably contain no Pb. The weight ratio thereof may actually be <=1,000 ppm expressed in terms of PbO. Thereby, the Curie point of the piezoelectric ceramics can be regulated to >=350 deg.C. |
