Patent · US Expired

Dielectric ceramics

US4830995A · kind A · utility

2Cited by
3References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 2, 1988
Grant dateMay 16, 1989
Priority date
Expiry dateSep 2, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC04B35/495
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A dielectric ceramic which has a composition represented by the following general formula (I) and having a substantially perovskite crystal structure: EQU (Ba.sub.1-x Sr.sub.x) (Mg.sub.1-y-w Ni.sub.y Co.sub.w).sub.1-u (Ta.sub.1- Nb.sub.z).sub.u 0.sub.p (I) wherein x, y, z, u, w and p satisfy one selected from the following conditions: x=0, w=0, z=0, 0.001.ltoreq.y.ltoreq.0.088, 0.66.ltoreq.u<0.72, and p represents a number with which the charges of the cations of Ba, Mg, Ni and Ta are neutralized, whereby the entire composition is electrically neutralized; x=0, z=0, 0.001.ltoreq.y.ltoreq.0.40, 0.001.ltoreq.w.ltoreq.0.40, 0.61.ltoreq.u.ltoreq.0.72, 0.002.ltoreq.y+w.ltoreq.0.40 and p represents a number with which the charges of the cations of Ba, Mg, Ni, Co and Ta are neutralized, whereby the entire composition is electrically neutralized; x=0, w=0, 0.04.ltoreq.y.ltoreq.0.90, 0.10.ltoreq.z<0.96, 0.61.ltoreq.u.ltoreq.0.72, and p represents a number with which the charges of the cations of Ba, Mg, Ni, Nb and Ta are neutralized, whereby the entire composition is electrically neutralized; and w=0, 0<x.ltoreq.0.25, 0.ltoreq.y.ltoreq.0.5, 0.ltoreq.z.ltoreq.0.8, 0.61.ltoreq.u.ltoreq.0.72, …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.