Patent ID: 7408292

Claim:
A piezoelectric ceramic material having a general composition of ABO 3 , the piezoelectric ceramic material comprising: lead zirconate titanate having a perovskite lattice structure, wherein A stands for A positions in the perovskite lattice structure and B stands for B positions in the perovskite lattice structure, the lead zirconate titanate comprising at least a proportion of lead zirconate titanate of Pb 1−3x/2−y/2 SE x γ x/2−y/2 Cu I y (Zr 0.5515−z Ti 0.4485+z )O 3 , wherein: γ is a vacancy in a crystal lattice of the lead zirconate titanate; a value of x is from about 0.01 to about 0.04; a value of y is from about 0 to about the value of x divided by two; SE is a rare-earth metal selected from the group consisting of La, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tu, Yb, Lu and Y, x is determined by a valence of the rare-earth metal, and z is selected based on the value of y such that the piezoelectric ceramic material corresponds to a morphotropic phase boundary.