Europium-activated red luminescent matl. - based on gadolinium-yttrium- or lanthanum oxide and prepd. using sulphur-bearing fluxes

摘要

A rare-earth metal activated luminescent matl. based on the oxides of Gd, Y or La, is prepd. by heating their oxalates or nitrates in presence of a flux. The novelty is that the flux consists of a sulphur-bearing matl. and is mixed with the matl. to be heated in an amt. of 0.01-10, pref. 0.1-8, and esp. 0.5-5 wt.%. The pref. fluxes are the sulphur cpds. of the alkali(ne earth) metals, or heavy metal sulphides, esp. the sulphides of Bi, Sb or Cd. The advantage is that only a small amt. of flux is needed and it gives better crystal formation and more rapid grain growth. The matl. is for use in a CRT.