RARE EARTH FLUORESCENT SUBSTANCE FOR INTENSIFYING SCREEN AND INTENSIFYING SCREEN USING THE SAME

摘要

PROBLEM TO BE SOLVED: To improve dispersibility of a terbium activated gadolinium oxysulfide type phosphor for intensifying screen thereby forming a fine phosphor membrane on the intensifying screen enabling the improvement of resolution and X-ray excitation brilliance by coating the surface of a phosphor particle of a specific composition with silica particulates. ;SOLUTION: This rare earth phosphor for the intensifying screen is a phosphor particle represented by the formula: Gd₂O₂S:Tb with the surface coated with silica particulates. The silica particulates have an average diameter of preferably 3-100 nm, more preferably 4-20 nm. As silica particulates there can be mentioned aerosol silica, precipitated silica, silica aerogel, etc. The amount of the silica particulates is preferably 0.0005-1.2 wt.%, especially preferably 0.01-0.07 wt.% based on the terbium activated gadolinium oxysulfide type phosphor particles. The surface treatment is carried out by stirring phosphor particles in pure water, adjusting the pH of the mixture to obtain an alkaline solution, which is added to a dispersion of silica particulates, to which is then added zinc nitrate, zinc sulfate, etc., to allow the silica particulates adsorb on the surface of the phosphor particle.;COPYRIGHT: (C)1999,JPO