Granular rare earth phosphates having characteristic morphology

Abstract

Monodisperse particulates of a rare earth phosphate having the formula LnPO.sub.4 in which Ln is at least one rare earth, the average particle size of which ranging from 1 to 20 microns and preferably from 2 to 6 microns, and having a dispersion index of less than 0.5, preferably less than 0.4, are well suited as luminophors or precursors thereof, and are prepared via precipitation with phosphate ions at a substantially constant pH below 2, from rare earth salt solutions.

Dependencies are inferred from the claim text.