US 7,605,522 B2 · Piezoelectric device

Abstract

A piezoelectric device is formed by simultaneously firing a piezoelectric ceramic mainly composed of a perovskite complex oxide represented by general formula ABO3 and electrodes mainly composed of copper. The piezoelectric ceramic is represented by Pbα−aMea[(MII1/3MV(2+b)/3)zTixZr1−x−z]O3 (wherein Me represe element, MII is an acceptor element which is a divalent metal element, and MV is a donor element which is a pentavalent metal element), and satisfies equations 0.05≦z≦0.40, 0<bz/3≦0.035, 0.345≦x≦0.480, 0.965≦α≦1.020, and 0≦a≦0.05. In other words, the B sites contain excessive donors, and thus a piezoelectric device having good piezoelectric characteristics can be obtained even in the cases where a base metal material mainly composed of inexpensive copper is used as the internal electrode material.

Claims10

Dependent claims

A piezoelectric device formed by simultaneously firing a piezoelectric ceramic mainly composed of a perovskite complex oxide represented by general formula ABO3 and electrodes mainly composed of copper, wherein the perovskite complex oxide contains lead in the A sites, and titanium, zirconium, an acceptor element MII comprising a divalent metal element, and a donor element MV comprising a pentavalent metal element in the B sites, and equations below are satisfied:

0.05≦z≦0.40
0<bz/3≦0.035
0.345≦x≦0.480
wherein z is the total molar content of the acceptor element MII and the donor element MV in the B sites, the blend molar ratio of the acceptor element MII to the donor element MV is 1:(2+b), and x is the molar content of titanium in the B sites.

1 more element

Dependencies are inferred from the claim text.

Piezoelectric device

Life of this patent

Piezoelectric device

Life of this patent

Abstract

Claims10