The Effect of Partial Substitution of Sulfur on the Structural Properties of Amorphous Selenium

Amorphous samples of Se, SSe40, SSe30 and SSe10 were prepared as bulk glasses by air quenching. The structural properties of these samples were studied applying X-ray diffraction using Cu-kα radiation. The RDF analysis of the short range order (SRO), revealed no significant change in the bond length of the Se-Se pairs upon S substitution. The second nearest neighbor suffered a systematic increase in the bond length, where it increases from 3.697Å for pure Se to 3.896, 3.865 and 3.853Å for SSe40, SSe30 and SSe10, respectively. A similar change in the third nearest neighbor was also found for pure Se, SSe40 and SSe30, respectively, but for SSe10 the bond length increased in comparison with the other compositions. The variations in the coordination number were found to be composition dependent for the prepared samples. The structure was interpreted in terms of the extracted structural parameters and bond angles.