Rare earth phosphate, its production process and rare earth phosphate phosphor

摘要

A rare earth phosphate which has a compositional formula of LnxCeyTbzPO4 wherein Ln is at least one element selected from the group consisting of La, Gd and Y, and x, y and z are numbers which satisfy 0</=x<1, 0</=y</=1, 0</=z</=0.4 and x+y+z=1, and which has a powder reflectance after calcination at a temperature of from 120 to 900 DEG C in the air, of at least 99% of the reflectance of a MgO powder at a wavelength of 490 nm, its production process, a phosphor using said rare earth phosphate and its production process. <IMAGE>