Patent ID: 7176155

Claim:
A piezoelectric/electrostrictive ceramic composition containing, as a major component, a Pb(Mg 1/3 Nb 2/3 )O 3 —PbTiO 3 —PbZrO 3 ternary solid solution system composition and further containing Ni in an amount of 0.05 to 3.0% by mass in terms of NiO and Si in an amount of 0.003 to 0.0 1% by mass in terms of SiO 2 , wherein the Pb(Mg 1/3 Nb 2/3 )O 3 —PbTiO 3 —PbZrO 3 ternary solid solution system composition is presented by the following compositional formula(1): Pb x (Mg y/3 Nb 2/3 ) a Ti b Zr c O 3 (1): wherein x is 0.95≦x≦1.05; y is 0.8≦y≦1.0; a, b and c are decimals defined by a range, in coordinates formed by three coordinate axes of a, b and c, a range of (a,b,c)=(0.550, 0.425, 0.025 ), (0.550, 0.325, 0.125), (0.375, 0.325, 0.300),(0.100, 0.425, 0.475), (0.100, 0.525. 0.375)and (0.375, 0.425, 0.200); and a+b+c =1.000.