抄録
Hexagonal GdF3:Tm3+, which is thermodynamically unstable at room temperature, was successfully crystallized in borosilicate glass using a phase separation technique. The crystal structure of GdF3 was controlled by the addition of alkaline earth metals to the glass composition. Increasing the amount of SrF2 added to the glass composition to 1.65 mol % increased the amount of precipitation of hexagonal GdF3:Tm3+ crystals and the luminescence intensity. Lanthanide trifluoride phosphors were restrictively obtained in the borate phase as a result, and the emission of Tm3+ at 458 nm was observed. Furthermore, the luminescence intensity of GdF3:Tm3+ in the phase separation glass upon SrF2-doping was about three times larger than that without doping.
