PIEZOELECTRIC PORCELAIN COMPOSITION

摘要

A piezoelectric porcelain composition which comprises (a) perovskite type PbZrO<SUB>3</SUB>, (b) perovskite type PbTiO<SUB>3</SUB>, (c) SrO, (d) Nb<SUB>2</SUB>O<SUB>5</SUB> and (e) ZnO, wherein when the composition is represented by the general formula: Pb(Zr<SUB>a</SUB>Ti<SUB>1-a</SUB>)O<SUB>3</SUB> + bSrO + cNbO<SUB>2</SUB>.<SUB>5</SUB> + dZnO, respective relative amounts of (a) component, (b) component, (c) component, (d) component and (e) component satisfy the followings: 0.51 = a = 0.54, 1.1 X 10<SUP>-2</SUP> = b = 6.0 X 10<SUP>-2</SUP>, 0.9 X 10<SUP>-2</SUP> = c = 4.25 X 10<SUP>-2</SUP>, 0.1 X 10<SUP>-2</SUP> = d = 1.25 X 10<SUP>-2</SUP>, and 2.9 = c/d = 15.0. The above piezoelectric porcelain composition can provide an piezoelectric element which exhibits high values for both a piezoelectric strain constant (d<SUB>33</SUB>) and a Curie temperature (Tc).