Compositions – Inorganic luminescent compositions – Compositions containing halogen; e.g. – halides and oxyhalides
Patent
1989-06-07
1990-05-29
Cooper, Jack
Compositions
Inorganic luminescent compositions
Compositions containing halogen; e.g., halides and oxyhalides
C09K 1178
Patent
active
049293869
ABSTRACT:
A process is disclosed for preparing a single phase M'YTaO.sub.4 :Nb X-ray phosphor which comprises firing a uniform milled mixture consisting essentially of the components of Y.sub.2 O.sub.3, Ta.sub.2 O.sub.5, and Nb.sub.2 O.sub.5 in an amount equal to the stoichiometric amounts to form the phosphor, with a flux consisting essentially of lithium sulfate and potassium sulfate in a mole ratio of about 80 to 20, wherein the flux makes up from about 25% to about 50% by weight of the mixture. The firing is done by heating in a furnace to a temperature of from about 1200.degree. C. to about 1300.degree. C. at a heating rate of from about 1.0.degree. C. per minute to about 1.5.degree. C. per minute and maintaining the temperature for about 10 to 14 hours to react the components and produce a fired material containing luminescent material. The material is cooled by turning off the heat to the furnace and allowing the fired material to remain in the furnace until the temperature in the furnace is no higher than about 300.degree. C. The material is washed, dried, and classified to obtain a -325 mesh particle size. The phosphor essentially free of the impurity phases of Y.sub.3 TaO.sub.7, the freedom from the impurity phases resulting in an improvement in brightness over phosphors produced by prior methods and having the impurity phases present.
REFERENCES:
patent: 3459674 (1969-08-01), Emoto et al.
patent: 4024069 (1977-05-01), Larach
patent: 4225653 (1980-09-01), Brixner
"On the Structural and Luminescent Properties of the M'LnTaO.sub.4 Rare Earth Tantalates", Brixner & Chen, Electrochem. Soc. 130 (12), 1983, 2435-43.
Cooper Jack
GTE Products Corporation
Quatrini L. Rita
Walter Robert E.
LandOfFree
Process for preparing a niobium activated yttrium tantalate X-ra does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for preparing a niobium activated yttrium tantalate X-ra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing a niobium activated yttrium tantalate X-ra will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-519418