文件类型:PDF文档
文件大小:1605K
A method wherein an aqueous solution of a fluoride, an aqueous solution of a Group 2 or Group 3 metal salt, and an aqueous solution of a rare-earth metal dopant are combined in a plurality of continuous feed streams to form a series of precipitates of a rare-earth doped Group 2 or Group 3 metal fluoride, and wherein the member of the series differ by the concentration of the associated rare-earth dopant cation in the feed stream, and wherein the series so prepared defines the threshold concentration range above which operation of the process results in a minimization of the particle size variability caused by small perturbations in the concentration of the rare-earth dopant.