Gte Sylvania Incorporated

Gte Products Corporation

Francis N Shaffer

James E Mathers

Charles F Chenot

Dominic T Palumbo, Deceased

Cerium-activated yttrium gadolinium phosphate x-ray phosphors having a particle size of from about 4 to about 12 micrometers are prepared by solid state reaction techniques and followed by a firing in a reducing atmosphere to insure the cerium activator is in the plus 3 valence state. The x-ray phosphors can be represented by the formula Y.sub.1-a Gd.sub.a Ce.sub.x PO.sub.4 wherein a is a value between about 0.05 and about 0.3 and x is a value between about 0.005 and 0.25. The foregoing phosphors under x-ray excitation have a main band peak emission of about 355 nanometers and a main band width of about 15 nanometers. The x-ray screens employing the phosphors are conventional screens wherein the phosphor is disclosed upon a substrate which is suitable for x-ray intensifying screens.

Cerium activated yttrium gadolinium phosphate x-ray phosphors, process

A mixture of starting materials, corresponding to an oxide composition within an area of the ternary diagram for (Hf,Zr)O.sub.2, A.sub.2 O, P.sub.2 O.sub.5 formed by connecting end member points defined by the molar compositions: 45 (Hf,Zr)O.sub.2 - 10 A.sub.2 O - 45 P.sub.2 O.sub.5 ; 45 (Hf,Zr)O.sub.2 - 45 A.sub.2 O - 10 P.sub.2 O.sub.5 ; and 10 (Hf,Zr)O.sub.2 - 45 A.sub.2 O - 45 P.sub.2 O.sub.5, reacts to form large single crystalline essentially hexagonal particles of a new compound (Hf.sub.1-x Zr.sub.x).sub.3-y A.sub.4y (PO.sub.4).sub.4, and an aqueous-soluble second phase removable by washing. The large single crystalline hexagonal particles are useful as the luminescent material in x-ray intensifying screens, with band emission which overlaps at least partially the absorption edge of an x-ray film base to give good image resolution without crossover distortion.

Hexagonal hafnium, zirconium phosphate luminescent material, method of

Luminescent materials, having the formula, M.sub.(3+x) WO.sub.(6+x) : yMn wherein M is an alkaline earth metal selected from the group consisting of calcium, barium and strontium, x has a value of from 0 to about 0.4 and y has a value of from 0.00005 to about 0.05, emit light at a wave length of from about 650 to about 750 nanometers when excited by long wave length ultraviolet light. The above phosphors are prepared by heating the desired decomposable alkaline earth metal salt, a manganese source and tungsten trioxide in air and under controlled temperature conditions.

Manganese activated alkaline earth tungstate phosphors and method of

An oxide composition of 3:1 (Hf.sub.1-x Zr.sub.x)O.sub.2 :P.sub.2 O.sub.5, and having the empirical formula (Hf.sub.1-x Zr.sub.x).sub.3 P.sub.2 O.sub.11, where x is in the range of about 0 to 0.5, is an effective luminescent material for use in x-ray intensifying screens, and also an effective luminescent material host for Eu.sup.+2 blue emmissions. The luminescent material is obtained in essentially single crystalline large particles when prepared in the presence of a magnesium fluoride flux.

(Hf.sub.1-x Zr.sub.x).sub.3 P.sub.2 O.sub.11 luminescent material,

An X-ray phosphor composition consisting essentially of a material having the formula

Growing community of inventors

Towanda, PA, United States of America

Francis N Shaffer