Piezoelectric ceramic composition, especially for piezoelectric ceramic filters, oscillators and vibrators, is based on a calcium-bismuth titanate and contains manganese carbonate

摘要

A piezoelectric ceramic composition is based on a calcium-bismuth titanate of specified composition and contains manganese carbonate. A novel piezoelectric ceramic composition comprises an auxiliary component of greater than 0 to 1.5 wt.% MnCO3 (calculated as Mn) and a main component of formula: (a) CaBi4Ti4O15; (b) (Ca1-xM'x)Bi4Ti4O15, where M' = a divalent metal other than Sr or a trivalent metal other than Bi and x = greater than 0 to 0.3; or (c) (Ca1-xM2x/3)Bi4Ti4O15, where M = a trivalent metal other than Bi and x = greater than 0 to 0.45. An Independent claim is also included for a piezoelectric ceramic device comprising electrodes (14a, 14b, 14c) and a piezoelectric ceramic (12) of the above composition.