Ceramic compositions for BZN dielectric resonators
US5449652A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1994 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Sep 20, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/495
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A dielectric ceramic composition comprising a sintered mixture represented by the formula: EQU Bi.sub.2-x (Zn.sub.(2+y)/3 Nb.sub.4/3)O.sub.7-3x/2+y/3 where: 0.240.ltoreq.x.ltoreq.0.333, and 0.120.ltoreq.y.ltoreq.0.300; and a dielectric composition given by the formula: EQU (Bi.sub.1-z Ca.sub.z).sub.2-x (Zn.sub.(2+y)/3 Nb.sub.4/3)O.sub.7-3x/2+y/3+xz/2-z where: 0.ltoreq.x.ltoreq.0.667, 0.ltoreq.y.ltoreq.0.300, and 0<z.ltoreq.0.200; substitutions for Bi can be selected from the group consisting of Ca, Sr, Ba, Y, Pb, Cd, La and other rare earth oxides having atomic numbers 58-71 of the periodic table; substitutions for Zn can be selected from the group consisting of Mg, Ca, Co, Mn, Ni, and Cu; and substitutions for Nb can be selected from the group consisting of Ti, Zr, Hf, and Ta; wherein the substitutions comprise less than 20 mol % based on the Bi, Zn, and Nb content respectively. Typically, BZN and calcium-modified BZN ceramics are prepared by the initial preparation of a ZnNb.sub.2 O.sub.6 precursor; mixing of ZnNb.sub.2 O.sub.6 with Bi.sub.2 O.sub.3, CaCO.sub.3, and/or ZnO; calcination to form a ceramic powder having two distinct crystalline phases with nominal stoichiometries of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.