| 摘要 |
NEW MATERIAL:A phosphor of the formula I (wherein MII is Ba, Sr or Ca; X and X' are each independently Cl, Br or I, provided that X=X'; X'' and X'''''' are each independently X or F; 0.1<=a<=10.0; 0<b<=10.0; 10<-6=c<=2X10<-2>; and 0<x<=0.2). EXAMPLE:A phosphor of the formula II. USE:An Eu<2+>-activated composite halide phosphor which exhibits an excellent stimulated luminescence brightness (near ultraviolet - blue) when excited with an electromagnetic wave of 450-1,000nm after exposure to a radiation and useful for a radiation-activated screen and a radiation image converting panel. PREPARATION:Raw materials of phosphor such as at least two alkaline earth metal halides selected from among BaCl2, SrBr2, CaI2, etc., at least one cesium halide selected from among CsF, CsBr, etc. and a tin halide selected from among SnF2, SnCl2, etc. and a halide, oxide, etc. of Eu are mixed in an amount ratio corresponding to the formula III. The mixture is calcined in a neutral or weakly reducing atmosphere at 400-1,300 deg.C for 0.5-6hr.
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