The Synthesis and Particle Growth Mechanism of Bright Green Phosphor  YAG  : Tb

Abstract

The conventional method of preparing YAG:Tb requires repeated firing to form single-phase cubic material. When a SrF~, BaF2, YFa, or A1F3, or A1F3 is used as a reaction reagent, however, only a single firing produces ingle-phase cubic material. The solid-liquid phase reaction occurs during firing between the raw oxide materials as well as other by-products. X-ray diffraction patterns identify these by-products as YAM, YAP, YF3, YOF, and BaA1204 (SrA12Q). The particle growth is facilitated by a process in which small YAG particles first gather in the contact area between large YAG'particles where fluoride melts and forms a liquid film, then dissolve and finally precipitate when saturated to reduce the sur-face energy. There is an increasing demand for bright and high reso-lution picture displays. The high density television (HDTV), which is one such display, has been actively devel-oped and continuously improved in recent years. We have concentrated on improving the phosphor screen to give a higher brightness and higher resolution cathode-ray tube (CRT). To meet this goal, smaller particle and brighter