ZNS PRECIPITATION - MORPHOLOGY CONTROL

ZnS is the most important base material for cathode-ray tube luminesce nt materials. In order to meet the requirements of various types of lu minescent screen, routes to ZnS powder with adjustable particle morpho logy were investigated. The most important morphological parameters of ZnS phosphors are the particle size and the particle size distributio n. Industrially, ZnS synthesis is performed by precipitation in an aqu eous medium. Precipitation methods included in this study are homogene ous precipitation, precipitation in liquid crystal phase and the intro duction of seeds. The powders received were processed to luminescent m aterials in a standard manner. The results are discussed in relation t o raw ZnS powder properties as well as to the morphology and performan ce of the resulting annealed phosphor powders. From the methods invest igated, the use of seed sols based on nanosized CuS, ZnS and S particl es yielded the best results, namely, well-defined phosphor particles o f micron-scale diameter.