Process for producing Ce-Mn coactivated fluoroapatite phosphors as the yellow emitting component for high efficacy lamp blends

摘要

Yellow emitting fluorescent lamp phosphor compositions comprise cerium and manganese activated alkali-earth fluoroapatite compositions containing sodium having the approximate formula (Ca1-sSrs)tCevNawMnx(PO4)yFz wherein s is from 0 to 1 t is from about 3.43 to about 4.01 v is about 0.3 w is about 0.3 x is from about 0.3 to about 0.4 y is about 3.00 z is from about 1.0 to about 4.0. An improved two step firing process for producing the disclosed phosphors is described and an improved fluorescent lamp employing the disclosed phosphors is also described.