PIEZOELECTRIC CERAMICS, PIEZOELECTRIC ELEMENT AND LAMINATED PIEZOELECTRIC ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide lead-free piezoelectric ceramics whose strains show little temperature dependency near a phase transition temperature. SOLUTION: The piezoelectric ceramics essentially comprise a BaTiO3 ceramics composition and do not satisfy the Curie-Weiss' law: ε=C/(T-T0 ) (provided that ε is the dielectric constant; C is the Curie constant; T is a given temperature in a paraelectric phase; and T0 is the Curie-Weiss temperature).