Abstract: The phosphor and the X-rays intensifing screen according to the present inventin emit light by the excitation of X-ray, and they are used for medical and industrial radiography. In addition to the conventional contents of rare earth tantalate and/or rare earth niobate, the phosphor according to the present invention contains a determined quantity of divalent metal. This divalent metal content can make the improvement of the afterglow characteristic and the light emission characteristic of the phosphor. The phosphor according to the present invention is represented by the general formula (I) MyLn.sub.1 -x-(2/3)yDO.sub.4 : xR.sup.3+ (I).

Abstract: This invention relates to rare earth tantalate and/or niobate phosphors which emit light under X-ray excitation, and an X-ray intensifing screen which utilizes these phosphors. The phosphor is represented by the general formula (I);.sup.Ln 1-x-(2/3)y-(1/3)z.sup.M" y.sup.M' z.sup.DO 4:xR.sup.3+(I)In this formula, M" is at least one kind of divalent metal selected from the group consisting of Be, Mg, Ca, Sr, Zn and Cd, M' is at least one kind of alkali metal selected from the group consisting of Li, Na, Ba and K, Ln is at least one kind of element selected from the group consisting of Y, Gd, La and Lu, D consists of Ta and/or Nb, and R is at least one selected from the group conssiting of Tm, Pr, Sm, Eu, Tb, Dy and Yb, y is a value in the range 1.times.10.sup.-5 .ltoreq.y.ltoreq.1, z is a value in range 1.times.10.sup.-4 .ltoreq.z.ltoreq.0.1, and x is a numerical value in the range 0.ltoreq..times..ltoreq.0.05.

Abstract: A phosphor for an X-ray intensifying screen contains a phosphor mixture of a phosphor represented by BaFBr:mEu.sup.2+ (5.times.10.sup.-4 .ltoreq.m.ltoreq.5.times.10.sup.-2), and a phosphor represented by Y.sub.1-2/3.times. M.sup.x TaO.sub.4 :nNb (10.sup.-5 .ltoreq..times..ltoreq.1, 0.ltoreq.n.ltoreq.0.05, and M is at least one member selected from the group consisting of Ca, Sr, and Cd). An X-ray intensifying screen includes a support and a phosphor layer formed on the support and containing the above phosphor. When this X-ray intensifying screen is used, an X-ray image producing less crossover light and having high graininess and sharpness can be obtained. An exposure amount of an object to be examined can be reduced in medical radiophotography, and radiation diagnostic performance can be improved.

Abstract: The phosphor and the X-ray intensifying screen according to the present invention emit light by the excitation of X-rays and they are used for medical and industrial radiography. In addition to the conventional contents of rare earth tantalate and/or rare earth niobate, the phosphor according to the present invention contains a determined quantity of divalent metal. This divalent metal content can make the improvement of the afterglow characteristic and the light emission characteristic of the phosphor.The phosphor according to the present invention is represented by the general formula (I)MyLn.sub.1 -X-.sub.(2/3) yDO.sub.4 : xR.sup.3+ (I).

Abstract: A phosphor material for a radiation intensifying screen includes phosphor particles which emit light upon radiation excitation, and alkaline-earth metal fluoride. The alkaline-earth metal fluoride is formed in situ on the surface of the phosphor particles through a reaction of a first reactant containing the alkaline-earth metal with a second reactant containing the fluoride to improve the dispersibility of the phosphor particles. The phosphor material is dispersed in a binder and coated on a base support as a phosphor layer to provide a radiation intensifying screen.