| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric porcelain compsn. usable for a resonator in a wide frequency range by using lead titanate contg. lanthanoids substd. for part of Pb as a principal component and incorporating Nb2O5 and MnO2 as subsidiary components. SOLUTION: The piezoelectric porcelain compsn. contains a principal component represented by the formula and 0.05-2.5 wt.% Nb2O5, 0.05-2.5 wt.% MnO2 and <=0.5 wt.% ZrO2 as subsidiary components, based on 100 wt.% of the principal component when 1 mol weight of the principal component is represented by 100 wt.%. The sinterability of the compsn. is enhanced by substituting one or more selected from Ca, Sr and Ba for <=25 at.% of Pb. Principal components such as PbO, TiO2, La(OH)3 and CaCO3 are mixed with subsidiary components such as MnO2 and ZrO2 in a prescribed ratio, the powdery mixture is calcined at about 950 deg.C and prescribed amts. of Nb2O5 and, optionally, CuO are added to the resultant calcined body. They are comminuted, mixed and press-molded. The molding is fired in an oxygen atmosphere at 1,000-1,300 deg.C to obtain the piezoelectric porcelain compsn. In the formula, 0.01<=x<=0.40 and M is one of more selected from La, Nd, Pr, Ce and Sm. |
