PREPARATION OF LANTHANUM,CERIUM,AND TERBIUM PHOSPHATE PHOSPHOR HAVING IMPROVED LUMINANCE

摘要

PURPOSE: To obtain a lanthanum cerium terbium phosphate phosphor having high brightness in a cost-effective and efficient manner by reacting a single- phase, mixed valence state lanthanum cerium terbium oxide with boron phosphate in the presence of a fluxforming compd. and separating the formed phosphor from boron oxide and dissociated ions. ;CONSTITUTION: A single-phase, mixed valence state lanthanum cerium terbium oxide is sintered in the presence of boron phosphate and a flux-forming compd. (e.g. lithium carbonate) for 1.5 to 4 hr at 1,150 to 1,300°C which is suitable for the formation of a mixture comprising a lanthanum cerium terbium phosphate phosphor, boron oxide, and ions dissociated from the fluxforming compd. The sintered cake is pulverized. The powder is washed in 2% dilute nitric acid at 90°C for 4 hr, thereby separating the phosphor from boron oxide and dissociated ions, and then washed with high-temp. deionized water to obtain the contemplated phosphor.;COPYRIGHT: (C)1992,JPO