White, green, and yellow photoluminescence in the (CaO $\cdot$ Al$_2$O$_3$ $\cdot$ SiO$_2$):Eu system

It is shown that nitrogen-laser excited (2CaO $\cdot$ $m$(Al$_2$O$_3$) $\cdot$ SiO$_2$) : Eu photoluminescent phosphors obtained by direct solid-state synthesis at 1350$^\circ$C emit white, green, and yellow lights when Al$_2$O$_3$ content m in the system decreases from 0.40 to 0.05. The coordinates of these colors correspond to the coordinates of light warning systems according to International Commission on Illumination (CIE) and are close to the coordinates of primary colors in the EBU and NTSC TV standards.