Piezoelectric Ceramics of Pb(Zr–Ti)O3 Modified by A1+B5+O3 or A3+B3+O3

Abstract

The properties of the solid solutions (Pb_1-x –A _x )((Zr _y –Ti_1-y )_1-x –B _x )O₃ or (1-x)Pb(Zr _y –Ti_1-y )O₃–xABO₃ are studied, where A is a mono- or trivalent ion and B a penta- or trivalent ion as follows: A¹⁺=K, Na, B⁵⁺=Sb, Nb, Bi; A³⁺=Bi, La, B³⁺=Fe, Al, Cr. The composition ranges examined are mostly within xy3 ceramics are improved by the present modification with ABO₃; that is, the dielectric constant increases and the electromechanical coupling coefficient first increases to a broad maximum and then decreases. The coupling coefficient over 0.5 is easily obtained even for less dense ceramics, especially in the case of NaNbO₃ substitution.