| 摘要 |
An X-ray intensifying screen based on a tantalate phosphor, said phosphor having the monoclinic M min structure and selected from the following: (a) YNbxTa1-x04 where x is 0 to about 0.15; (b) LuNbxTa1-x04 where x is 0 to about 0.2; (c) Y1-yTmyTa04 where y is 0 to about 0.03; (d) a solid solution of (a) and (b); (e) a solid solution of (a) and (c); (f) Y1-yTb04 where y is about 0.001 to about 0.15; (g) Lu1-yTbyTa04 where y is about 0.001 to about 0.15; (h) Gd1-yTbyTa04 where y is about 0.001 to about 0.15; (i) a solid solution of at least two of (f), (g) and (h); (j) any of (a) to (i) wherein up to 45 mole percent of the yttrium, lutetium of gadolinium is replaced by lanthanum; (k) any of (a) to (i) wherein up to 15 mole percent of the yttrium, lutetium of gadolinium is replaced by ytterbium; and (i) any of (a), (b), (c), (d) and (e) wherein up to 15 mole per cent of the ytterium or lutetium is replaced by gadolinium. The invention also includes a process for producing tantalate phosphors which involves mixing the precursor oxides with a flex comprising Li2SO4, LiCl, or a eutecitic mixture of BaCl2/LiCl and firing at a temperature below 1450 DEG C. |
