Optical properties of Cr^(3+) doped Na_5Lu_9F_(32) single crystals grown by the Bridgman method

The growth of Na5Lu9F32 single crystals doped with Cr3＋ ions in 0.1 mol%, 0.2 tool% and 0.5 mol% concentrations by Bridgman method was reported. The optical absorption and luminescence spectra decisively demonstrate that the Cr dopant enters Na5Lu9F32 as Cr3＋. Fluorescence emission at wavelengths of 418 nm, 444 nm, 653 nm and 678 nm can be observed under the excitation of 372 nm and the fluorescence lifetime at 418 nm was measured to be^10.31 μs. The possible crystal sites for Cr3＋ ions in Na5Lu9F32 single crystal were discussed, and the lattice parameter Dq, Racach parameters B and C were estimated.