Fluorescence and structure of barium zirconium trisilicate

The compound BaZrSi ₃O ₉ is isomorphous with benitoite. Under cathode-ray excitation it shows an emission with a maximum at 285 nm. This emission is ascribed to the Zr ⁴⁺ ions. Activation with Ti ⁴⁺ or Eu ²⁺ yields efficient photoluminescent phosphors. It is further shown that the blue-green emission observed for a number of zirconium compounds is due to Ti ⁴⁺ impurities and that the Zr ⁴⁺ emission itself lies in the ultraviolet.