Patent ID: 7387745

Claim:
A piezoelectric ceramic material comprising lead zirconate titanate (PZT) having the formula Pb 2+ (Zr 4+ ,Ti 4+ )O 3 2− and the crystal structure of perovskite having the formula A 2+ B 4+ O 3 2− , characterized by substitution of partially valence compensating acceptor and donor ion pairs B 3+ y /B 5+ z for the formation of only partially valence compensated compositions of the system Pb 2+ 1−w Sr 2+ z [B 3+ y (Zr x Ti 1−x ) 4+ 1−y−z Nb 5+ z ]O 2− 3 wherein w=0.00 to 0.005, x=0.50 to 0.55, y<z, and z=0.00 to 0.05, wherein a coupled substitution of heterovalent acceptor and donor ions at Zr/Ti sites is present in the material and the B 4+ site is occupied by Al 3+ or Fe 3+ ions.