Process of preparing tantalate x-ray intensifying phosphors with decreased delayed fluorescence

摘要

Process for preparing an X-ray intensifying phosphor chosen from a group comprising. (a) YnbxTa1-xO4, where x = 0-0.15; (b) LuNbxTa1-xO4, where x = 0-0.2; (c) Y1-yTmyTaO4, where y = 0-0.03; (d) a solid solution of (a)+(b); (e) a solid solution of (a)+(c); (f) Y1-yTbyTaO4, where y = 0.001-0.15; (g) Lu1-yTbyTaO4 where y = 0.001-0.15; (h) Gd1-yTbyTaO4 where y = 0.001-0.15; (i) solid solution of at least two of (f)+(g)+(h); (j) any of (a)-(i) where up to 45 mol.% of the Y, Lu, Gd is replaced by La; (k) any of (a)-(i) with 15 mol.% of Y, Lu, Gd replaced by Tb; (l) any of (a)-(e) with up to 15 mol.% of the Y, Lu replaced with Gd; and (m) Y1-xBixTaO4 where x = 0.00005 - 0.1. The process comprises; (i) intimately mixing stoichiometric quantities of the precursor oxides; (ii) mixing (i) with a flux of 2-95 wt.% KCl, 5-98 wt.% of Li salt chosen from LiCl and Li2SO4, and 0-50 wt% SrCl2; (iii) heating (ii) for 3 hrs. at 1,100-1,400[deg]C; and (iv) recovering the phosphor. Also claimed is a radiographic recording element utilising the phosphors.