Raman spectra of AsxSe100-x glasses doped with metals

Chalcogenide glasses in the system AsxSe100=x, as well as As40Se60 and As50Se50 glasses doped with metals (Bi, Ge, Cd, Ag, Sn, Mn, Dy and Sm) were investigated by Raman spectroscopy. The Raman spectra of AsxSe100-x with 0 <= x <= 10 suggest that the majority building units are Se chains and See closed rings. At higher As contents, new structural units are formed from As and Se atoms. The Raman profiles for x > 50 are characterized by the presence of strong narrow bands indicating the high ordering in the structure of these glassy materials. The doped samples with small amounts of metals, 0.1 - 1.0 at.%, do not show appreciable changes in their short-range order structure, with the exception of the 0.5 at.% Dy-doped sample. For the sample As50Se50+7.5 at.% Sn, there is direct evidence for the formation of new Sn-based structural units, such as Sn(Se-1/2)(4) tetrahedra.