AMORPHOUS COMPOSITE OXIDE PARTICLE, ITS MANUFACTURING METHOD, FLUORESCENT MATERIAL AND FLUORESCENT SUBSTANCE

PROBLEM TO BE SOLVED: To provide an amorphous composite oxide particle which is spherical, has a small maximum diameter and has a narrow particle size distribution, its manufacturing method, a fluorescent material composed of the amorphous composite oxide particle and capable of easily forming a homogeneous and dense fluorescent film, and fluorescent substance as a structure having high red emission efficiency. SOLUTION: The manufacturing method is provided with a step for producing a mist by atomizing a mixed solution containing a compound that comprises a rare earth element (Eu, Tm, Er, Pr, Tb, Ce or the like) and an acidic silica sol, and a step for heat treating the mist at 600-1,500°C. Wherein preferred constituting ratio of the Si and the rare earth element in the mixed solution is 1-50 mol% and 99-1 mol% provided that the total of these is 100 mol%. COPYRIGHT: (C)2006,JPO&NCIPI