Piezoelectric ceramic composition and piezoelectric ceramic element using the same
US6734606B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2002 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Nov 21, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2235/604
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A piezoelectric ceramic composition includes a bismuth layered compound containing Sr, Bi, Nb and a metal element other than Bi having a valence of 3. The bismuth layered compound satisfies the relational expressions: 0.275<a/c<0.5; 0.9≦b/c≦1; 0<x/c≦0.175; and 0.5<(a+3x/2)/c≦0.7, where a, b, c and x represent the molar fractions of Sr, Bi, Nb, and the metal element other than Bi having a valence of 3, respectively. Thus, a piezoelectric ceramic composition mainly containing a bismuth layered compound whose bismuth content is equal to or less than the stoichiometric value and not substantially containing lead and which can be advantageously used for piezoelectric ceramic elements exhibiting a Qmax-factor sufficient for practical use can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.