Patent ID: 7498725
Filing Date: 2009-03-03
Classification: C04B,H01L

Abstract:
1. A piezoelectric ceramic composition comprising: a composite oxide, as a main component thereof, represented by the following composition formula (1) or (2); Cu as a first additive, in a content α, in terms of Cu at least one selected from Dy, Nd, Eu, Gd, Tb, Ho and Er, as a second additive, in a content β, in terms of oxide, falling within a range 0<β≦0.3% by mass, in relation to said main component; and at least one selected from Ta, Nb, W and Sb, as a third additive, in a content γ, in terms of oxide, falling within a range 0<γ≦0.6% by mass in relation to said main component; wherein:  a, x, y and z in the composition formula (1) satisfying the following relations, 0.96≦a≦1.03, 0.005≦x≦0.047, 0.42≦y≦0.53, 0.45≦z≦0.56, and x+y+z=1; and  a, b, x, y and z in the composition formula (2) satisfying the following relations, 0.96≦a≦1.03, 0<b≦0.1, 0.005≦x≦0.047, 0.42≦y≦0.53, 0.45≦z≦0.56, and x+y+z=1, and Me in the composition formula (2) representing at least one selected from Sr, Ca and Ba.