Process for production of lanthanum cerium aluminate phosphors
US5169557A · kind A · utility
Inventors
Key dates
| Filing date | Mar 20, 1990 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Mar 20, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K11/7774
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for production of lanthanum cerium aluminate phosphors represented by the formula EQU La.sub.1-x Ce.sub.x Al.sub.y O.sub.(3/2)(y+1) wherein 0.10<x<1 and 11.0.ltoreq.y.ltoreq.12.5, the phosphor exhibiting a predominantly blue peak emission. Lanthanum (III) oxide, cerium (IV) oxide, and aluminum hydroxide are blended together in the desired ratios, then precalcined in air at about 850.degree. C. The precalcined product is then fired in a reducing atmosphere at about 1600.degree.-1800.degree. C. for about 3-4 hours, pulverized, refired in a reducing atmosphere at about 1600.degree.-1800.degree. C. for about 3-4 hours, and again pulverized to form the phosphor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.