| 摘要 |
<p>A piezoelectric ceramic material is provided which can form a sintered piezoelectric ceramic compact having a low electromechanical coupling coefficient, a low resonant resistance and a low temperature dependence of the resonant frequency. The piezoelectric ceramic material is a solid solution having a primary component composed of PbTiO3, PbZrO3 and Pb(MaXMdY)O3, in which Ma is at least one bivalent element or trivalent element, and Md is at least one pentavalent element or hexavalent element, and the ratio X/Y of the Ma content X to the Md content Y is larger than the stoichiometric ratio. Preferred is Ma being Mn, Md being at least one of Nb, Sb, Ta and W, and when the contents of Mn, Nb, Sb, Ta and W are represented by A, B, C, D and E, respectively, 0.525<=A/(B+C+D+2E)<=1, and about 20 mole percent or less of the element Pb being replaced by at least one of Ca, Ba, Sr and La. Preferably, a sintered compact is obtained by firing this piezoelectric ceramic material in an oxygen atmosphere at an oxygen concentration of about 80% by volume or more is used in an unsaturated polarized state having an electromechanical coupling coefficient corresponding to about 80% or less of that of a sintered compact in a saturated polarized state.</p> |
