Piezoelectric ceramics
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiromu Ouchi, Masamitsu Nishida, Kazunori Numata
Life of this patent
Estimating the term…
Abstract
Ceramic materials within particular ranges of the ternary system Pb(Sn.sub.1/3 Sb.sub.2/3) O.sub.3 -PbTiO.sub.3 -PbZrO.sub.3 in solid solution form exhibit high planar coupling coefficient along with high dielectric constant, and are useful in electromechanical transducers. The ceramic materials are those within the area A, B, C, D, E and F of FIG. 2.
Claims6
A piezoelectric ceramic composition exhibiting high stability of resonant frequency with respect to temperature over the range of -40.degree. C. to 80.degree. C. comprising a solid solution of a material selected from the area bound by lines connecting points A, B, C, D, E and F of the triangular diagram of FIG. 2, wherein A, B, C, D, E and F respectively have the following formulae:
- A:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.01 Ti.sub.0.75 Zr.sub.0.24 O.sub.3
- B:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.01 Ti.sub.0.09 Zr.sub.0.90 O.sub.3
- C:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.09 Ti.sub.0.01 Zr.sub.0.90 O.sub.3
- D:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.50 Ti.sub.0.01 Zr.sub.0.49 O.sub.3
- E:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.50 Ti.sub.0.495 Zr.sub.0.005 O.sub.3
- F:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.25 Ti.sub.0.745 Zr.sub.0.005 O.sub.3 .
A piezoelectric ceramic material exhibiting high stability of resonant frequency with respect to temperature over the range of -40.degree. C. to 80.degree. C. consisting of the solid solution having one of the following formulae:
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.05 Ti.sub.0.44 Zr.sub.0.51 O.sub.3
- or
- Pb(Sn.sub.1/3 Sb.sub.2/3).sub.0.15 Ti.sub.0.44 Zr.sub.0.41 O.sub.3 .
Dependencies are inferred from the claim text.