| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric ceramic composition capable of being produced at a low firing temperature so as to control deviation or fluctuation of the composition resulting from evaporation of lead oxide by making the composition include a specific content of AgO as an auxiliary ingredient in a compound oxide of Pb, Zn, Nb, Sn, Ti and Zr as the main ingredient. SOLUTION: This piezoelectric ceramic composition comprises a compound oxide as the main ingredient and 0.02 to 2.5 wt.% (based on the main ingredient) of AgO as an auxiliary ingredient, the former being shown by the formula Pb(Zn1/3 Nb2/3 )A(Sn1/3 Nb2/3 )B(TiCZrDO3 [0.01<=A<=0.55; 0.01<=B<=0.25; 0<=C<=0.80; 0<=D<=0.88; and A+B+C+D=1]. It exhibits greatly improved dielectric constant, coupling coefficient and particularly mechanical Q level, when further incorporated with 0.05 to 5 wt.% of Cr2 O3 or MnO2 , based on the main ingredient, as another auxiliary ingredient. The piezoelectric ceramic composition is obtained by firing the composition comprising the main ingredient shown by the above formula and 0.02 to 2.5 wt.% (based on the main ingredient) of powdered AgO as the auxiliary ingredient, after it is formed into a shape. |
