Rare earth elements as a source of impurities in doped chalcogenide glasses

Abstract

Elemental and heterophase impurities in some rare-earth elements (Ce, Pr, Nd, Tb, and Dy) and features of their influence on optical and emission properties of doped chalcogenide glasses are determined. The main impurity elements in REEs are: W, Mo, Fe, Mg, Ti and some other metals (up to 8400 ppmw), fluorine and oxygen in the form of oxofluorides and oxides (up to 680 ppmw), and hydrogen in dissolved form (up to 68 ppmw). In doped Ge20Sb10Ga5Se65 glasses, the REEs are the main source of impurities of d-transition metals, non-metals (Si, F), gas-forming impurities (H, O), and inclusions. Heterogeneous inclusions, the source of which is REEs, make the greatest contribution to optical losses in doped chalcogenide glasses. Impurities of hydrogen in the form of SeH groups, oxygen in the form of dissolved oxides, d-transition metal ions, and REE analogues affect the rate of non-radiative relaxation of the excited state of REE.