Piezoelectric ceramic compositions
AssigneeMurata Manufacturing Co., Ltd.
InventorsKiyoshi Hase, Kosuke Shiratsuyu, Kunisaburo Tomono
Life of this patent
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Abstract
A three-component piezoelectric ceramic composition having a large electro-mechanical coupling coefficient and high mechanical strength, composed of xPb(Mg.sub.w/3 Nb.sub.1-w/3)O.sub.3 -yPbZrO.sub.3 -zPbTiO.sub.3, is adapted so as to place points representing the compositional proportions x, y, and z (x+y+z=1) on lines connecting points A: (x=0.70, y=0.01, z=0.29), B: (x=0.50, y=0.01, z=0.49), C: (x=0.05, y=0.40, z=0.55), and D: (x=0.05, y=0.65, z=0.30) and in the compositional region bounded by the lines in a three-component composition diagram and the value of w in the range from 0.8 to 1.
Claims10
A three-component piezoelectric ceramic composition of xPb(Mg.sub.w/3 Nb.sub.1-w/3)O.sub.3 -yPbZrO.sub.3 -zPbTiO.sub.3 in which up to about 15 molar percent of said Pb atoms are replaced with atoms of at least one element selected from the group consisting of Ca, Sr and Ba and x+y+z=1, wherein points representing the compositional proportions x, y, and z are on lines connecting points
- A:
- (x=0.70, y=0.01, z=0.29),
- B:
- (x=0.50, y=0.01, z=0.49),
- C:
- (x=0.05, y=0.40, z=0.55), and
- D:
- (x=0.05, y=0.65, z=0.30)
- or are within the region bounded by those lines in a three-component composition diagram, and the value of w is from about 0.8 to 0.95.
Dependencies are inferred from the claim text.