Method of preparing a luminescent Eu/sup 2+/ activated strontium aluminate

Patent · Tue Jan 03 00:00:00 EST 1989

OSTI ID:6408637

Pet, R J; Van den Nieuwenhof, M M.C.; Duisters, J P.H.M.

A method is described for preparing a luminescent Eu/sup 2+/ activated strontium aluminate defined by a formula Sr/sub 4/Al/sub 14/O/sub 25/:Eu/sup 2+/, in which a mixture comprising SrO, Al/sub 2/O/sub 3/, Eu/sub 2/O/sub 3/ or compounds yielding these oxides at the heating temperature employed and a flux is heated in a weakly atmosphere at a temperature of 1100/sup 0/ to 1500/sup 0/C. Per mol of the Al present, a combination of between 0.1 and 5 mol % of B/sub 2/O/sub 3/ or compounds yielding B/sub 2/O/sub 3/ at the heating temperature and between 0.1 and 10 mol % of at least one of the fluorides and/or chlorides of Ba, Sr, Cs and/or Al and/or RbCl is present as the flux. Per mol of the Al present, between 0.1 and 10 mol % of at least one ammonium halide is added as a flux to the so heated mixture; and the mixture thus obtained is subsequently heated at a temperature of 700/sup 0/ to 1200/sup 0/C to effect at least partial removal of flux residues present.

• Assignee: U.S. Phillips Corp., New York, NY
• Patent Number(s): US 4795588
• OSTI ID: 6408637
• Resource Relation: Patent File Date: Filed date 29 Mar 1988
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
CHEMICAL PREPARATION
STRONTIUM COMPOUNDS
ALUMINIUM
BARIUM
BORON OXIDES
CESIUM
CHEMICAL ACTIVATION
CHLORIDES
EUROPIUM
EUROPIUM OXIDES
FLUORIDES
HALIDES
HEATING
LUMINESCENCE
QUANTITY RATIO
RUBIDIUM
STRONTIUM
STRONTIUM OXIDES
VERY HIGH TEMPERATURE
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ALUMINIUM COMPOUNDS
BORON COMPOUNDS
CHALCOGENIDES
CHLORINE COMPOUNDS
ELEMENTS
EUROPIUM COMPOUNDS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
METALS
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
RARE EARTHS
SYNTHESIS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication