Abstract
Benitoite (BaTiSi3O9) phases, which were partially-substituted by germania (GeO2) in order to stabilize the phase, were synthesized, and their optical properties were examined. The benitoite phase was crystallized by a small quantity of Ge-introduction into the benitoite composition. Clear blue emission with the peak at ~430 nm, due to the transition of 3T1 → 1A1 in the TiO6 octahedra, was observed at room temperature during the ultraviolet excitation, being sufficient for a visual confirmation. On the other hand, the reduction in blue emission intensity by the Ge-introduction was confirmed. This was qualitatively explained on the basis of configurational-coordinate mode without discrepancy.
