Back to results
US 8,506,844 B2Granted
Rare-earth doped fluorides and process for preparing
AssigneeE. I. Du Pont de Nemours and Company
InventorsMichael Karl Crawford, Kurt Richard Mikeska
Life of this patent
Estimating the term…
Abstract
The present invention is directed to rare-earth doped solid state solutions of alkaline earth fluorides having novel luminescence properties, and to a process for preparing them. The invention is useful as identifying markers on articles. Other uses include phosphors for plasma displays, optical frequency multipliers, optical amplifiers and the like.
Claims10
A composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula
- REx(CaaSrbBac)1-xF2+x−2yOy
- wherein RE represents a three-valent rare-earth element, 0.005≦x≦0.20, and 0≦y≦0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero;
- the composition exhibiting a luminescence spectrum having a plurality of luminescence peaks at characteristic wavelengths, at least one pair of the luminescence peaks exhibiting an intensity ratio with respect to one another that differs by at least 5% from the corresponding intensity ratio of a corresponding reference composition.
Dependencies are inferred from the claim text.