Piezoelectric ceramic composition
US5648012A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1995 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Dec 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/853
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A piezoelectric ceramic composition comprising a perovskite compound which contains, as metal components, Pb, Sr, Zr, Ti, Nb, Cr, Y, Co and at least one element selected from La, Gd, Nd, Sm and Pr, and may further contain Sb or Na, wherein when the composition formula is expressed as, EQU (Pb.sub.1-x-.alpha.-y Sr.sub.x Na.sub..alpha. M.sub.y).sub.a [(Nb.sub.b Y.sub.c Cr.sub.d Co.sub.e Sb.sub..beta.).sub.f Ti.sub.g Zr.sub.1-f-g ]O.sub.3, wherein M is at least one element selected from La, Gd, Nd, Sm and Pr, then, x, y, a, b, c, d, e, f, g, .alpha. and .beta. satisfy the following relationships, 0.005.ltoreq.x.ltoreq.0.08, 0.002.ltoreq.y.ltoreq.0.05, 0.95.ltoreq.a.ltoreq.1.05, 0.47.ltoreq.b.ltoreq.0.70, 0.02.ltoreq.c.ltoreq.0.31, 0.11.ltoreq.d.ltoreq.0.42, 0.01.ltoreq.e.ltoreq.0.12, 0.02.ltoreq.f.ltoreq.0.15, 0.46.ltoreq.g.ltoreq.0.52, 0.ltoreq..alpha..ltoreq.0.005, 0.ltoreq..beta..ltoreq.0.13, and b+c+d+e+.beta.=1.00. The piezoelectric ceramic composition of the present invention exhibits a high electromechanical coupling coefficient Kp, a low mechanical quality factor Qm, a low dielectric constant .epsilon.r, excellent heat resistance, and can be preferably used as a piezoelectric …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.