METHOD OF PREPARING RARE EARTH METAL PHOSPHATE VANADATE LUMINESCENT COMPOSITIONS HAVING ACICULAR CRYSTAL HABIT

摘要

A method of preparing solid solutions of yttrium orthovanadate-ortaphosphate activated by metals selected from the rare earths of the lanthoxide series, which method comprises (a) precipitating from a stoichiometric hydrated yttrium orthophosphate solution containing an activating ratio metal of the rare earths of the lanthoxides series; (b) precipitating from a stoichiometric yttrium orthovanadate solution containing a metal activating ratio of the rare earths of the lanthoxide series; (c) mixing predetermined proportions of said precipitated orthophosphate and orthovanadate as desired in said final solid solution; and (d) calcining the resulting mixture at a temperature sufficient to effect the formation of a solid luminescent solution of said orthophosphate-orthovanadate, whereby the proportion of solid solution from orthovanadate to orthophosphate is maintained exactly at a predetermined value as provided in the raw mixture. (Machine-translation by Google Translate, not legally binding)