关键词: 发光中心, 稀土, 氟氯化钡

Abstract: Rare earth ions RE³⁺ doped in BaFCl should randomly replace the sites of barium ion Ba²⁺ and form defects RE_Ba^·. Their extra one positive charge may be compensated by different negatively charged defects, possiblly introduced in the crystals during various preparation conditions. In these cases the charge compensation defects would influence the local environment of the doped rare earth ions, modifying their site symmetry, and therefore different types of luminescence centers should be formed. The authors have investigated the luminescence centers in Ce³⁺ and Gd³⁺ ions doped BaFCl crystsls by fluorescence spectroscopy for samples, synthesized or post-treated under various chemical conditions. There might exist two types of luminescence centers. One is related to the associates of RE³⁺with F'₁, the other to the associates of RE³⁺ with O'_F.

Key words: Luminescence centers, Rare earth, Barium fluorochloride