THE LUMINESCENCE OF THE GARNET CA4ZRGE3O12

The compound Ca4ZrGe3O12 has garnet structure with Ca and Ge in the do decahedral and tetrahedral sites, respectively. The octahedral sites a re occupied by Ca and Zr. Upon host lattice i.e. germanate excitation four different emissions are observed, viz. from the GeO4 group (310 n n), from the zirconate group (530 Ka), from Fe3+ present as an impurit y (similar to 750 nm), and from a radiation-induced centre (400 nm). E nergy transfer between these centres has also been observed.