Patent ID: 8434856

Claim:
A piezoelectric oxide having a composition expressed by a compositional formula, (A,B,C)(D,E,F)O 3 , where each of A, B, C, D, E, and F represents one or more metal elements, A, B, and C represent A-site elements, D, E, and F represent B-site elements, O represents the oxygen atom, the B-site elements D, E, and F are different when two or all of the A-site elements A, B, and C are identical, the A-site elements A, B, and C are different when two or all of the B-site elements D, E, and F are identical, and the ratio of each of the total molar amount of the A-site elements and the total molar amount of the B-site elements to the molar amount of oxygen atoms may deviate from 1:3 within a range in which the composition expressed by the compositional formula (A, B, C)(D, E, F)O 3 can form a perovskite structure; wherein the composition of said perovskite oxide satisfies the conditions (1), (2), (3), and (4), 0.98 ≦TF ( P )≦1.01, (1) TF ( ADO 3 )>1.0, (2) TF ( BEO 3 )<1.0, and (3) TF ( BEO 3 )< TF ( CFO 3 )< TF ( ADO 3 ), (4) where TF(P) is a tolerance factor of the piezoelectric oxide expressed by the compositional formula (A, B, C)(D, E, F)O 3 , TF(ADO 3 ) is a tolerance factor of a compound expressed by a compositional formula ADO 3 , TF(BEO 3 ) is a tolerance factor of a compound expressed by a compositional formula BEO 3 , and TF(CFO 3 ) is a tolerance factor of a compound expressed by a compositional formula CFO 3 , and wherein the A-site elements comprise Bi as an essemntial element, may further comprise Ba, and are free of Pb.