While the itsutoria/gadoliniums/European Pia coprecipitation single distributed spherical grain null which, is obtained production manner of the itsutoria/gadoliniums/European Pia coprecipitation single distributed spherical grain with

摘要

PROBLEM TO BE SOLVED: To produce yttria/gadolinia/europia coprecipitated single-dispersed spherical particles useful as starting material for a phosphor. ;SOLUTION: An aq. soln. of mineral acid salts of yttrium, gadolinium and europium is heated to a temp. between 80°C and the b.p., urea is added to the soln, while maintaining the temp. to deposit basic carbonates of yttrium, gadolinium and europium and the resultant precipitate is separated by solid-liq. separation and fired at 660-1,300°C to produce the objective yttria/gadolinia/europia coprecipitated single-dispersed spherical particles represented by the formula (Y_aGd_bEu_c)₂O₃ [where (a), (b) and (c) show atom ratio, 0.01≤a≤0.98, 0.01≤b≤0.98, 0.10≤c≤0.10 and a+b+c=1].;COPYRIGHT: (C)1999,JPO