| 摘要 |
A red-emitting phosphor consists of a europium-activated yttrium or gadolinium mixed vanadate and arsenate or phosphate, q(Y, Gd)2O3.(1 - x)V2O5.x(As, P)2O5.pEu2O5 where <FORM:1074530/C4-C5/1> The phosphor has emission maxima at 615 and 619nm, and may be used in a colour television screen or a high-pressure mercury vapour lamp (300-600 DEG C.). The phosphor is prepared by repeated heating in air and grinding, e.g. heating for two hours at 700 DEG C., 1150 DEG C. and 1150 DEG C. Any ratio of yttrium to gadolinium or of phosphorus to arsenic may be used. The firing mixture may be non-stoichiometric, but excess vanadium leads to yellow-coloured vanadium oxides and excess rare earth gives white-fluorescing rare earth oxide. |
