Barium titanate powders
US4829033A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Feb 1, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/22
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Barium titanate based dielectric compositions having the general formula Ba.sub.(1-x-x'-x") Pb.sub.x Ca.sub.x' Sr.sub.x" Ti .sub.(1-y-y'-y") Sn.sub.y Zr.sub.y' Hf.sub.y" O.sub.3, wherein x, x', x" and y, y', y" represent mole fractions of the divalent and tetravalent cations and x and x' have independent value greater than 0.01 and less than 0.3 and x", y, y' and y" have independent values greater than zero and less than 0.3, such that the sum (x+x'+x") is greater than 0.01 and less than 0.4 and the sum (y+y'+y") does not exceed 0.4. Regardless of the specific composition selected, the products of the invention have a mean primary particle size in the range of 0.05 to 0.4 microns with a very narrow particle size distribution. The products are dispersible so that the mean particle size determined by image anaylsis and by sedimentation are comparable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.