Luminescent material
AssigneeU.S. Phillips Corporation
InventorsThomas Justel, Carolin Borgmann, Ferdinand Schuth
Life of this patent
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Abstract
A luminescent material of general formula Ln.sub.y/3 Na.sub.x-y (Al.sub.x Si.sub.192-x O.sub.384)(MO.sub.3).sub.z wherein 0<x<96, 0<y<96, y<x and z<20, and Ln comprises one or more elements chosen from the group formed by Sc, Y, La and the Lanthanides and wherein M comprises one or more elements chosen from the group formed by Mo, W, V, Nb and Ta. Luminescent materials of this general formula are relatively cheap and are very suitable for use in low pressure mercury discharge lamps of the three band type.
Claims11
Luminescent material of general formula
- Lny/3Nax-y(AlxSi192-xO384)(MO3)z
- wherein 0<x<96, 0<y<96, y<x and z<20, and Ln comprises at least one element from the group formed by Sc, Y, La and the Lanthanides, and at least one element from the group formed by Gd and Y, and wherein M comprises at least one element from the group formed by Mo, W, V, Nb and Ta.
Method for preparing a luminescent material of the general formula
- Ln.sub.y/3 Na.sub.x-y (Al.sub.x Si.sub.192-x O.sub.384)(MO.sub.3).sub.z
- wherein 0<x<96, 0<y<96, y<x and z<20, and Ln comprises at least one element from the group formed by Sc, Y, La and the Lanthanides, and at least one element from the group formed by Gd and Y and wherein M comprises one or more elements chosen from the group formed by Mo, W, V, Nb and Ta, said method comprising the following steps:
- suspending a porous mixed oxide of Al and Si into a watery solution of a salt of Ln until crystals are formed,
- isolating the crystals,
- heating a mixture of the crystals with a solid compound comprising M in the presence of a gas mixture comprising oxygen until a product results,
- cooling the resulting product, and
- heating the resulting product in the presence of a gas mixture comprising oxygen.
Luminescent material of the general formula
- Lny/3Nax-y(AlxSi192-xO384)(MO3)z
- wherein 0<x<96, 0<y<96, y<x and z<20, and Ln comprises at least one element from the group formed by Sc, Y, La and the Lanthanides, at least one element from the group formed by Tm, Ce, and Pr.
Luminescent screen comprising a bearer provided with a luminescent material of the general formula
- Lny/3Nax-y(AlxSi192-xO384)(MO3)z
- wherein M is a solid compound comprising one of an ammonium metallate and a metal oxide.
Dependencies are inferred from the claim text.