X-ray analysis of GeSeAg glasses

Glass sample of the (Ge Se3)100−xAgx system were prepared in the composition range from x=0 to x=25 at.%. Short range order (SRO) was examined by X-ray diffraction using Mo(Kα) radiation at room temperature. X-ray scattering curves have a first scattering peak (FSP) located at q ≈ 1 Å−1. FSP has a systematic increase in intensity with decreasing Ag concentration revealing a change of the intermediate range order (IRO). The coordination numbers and the bond lengths of the correlation Ge–Se, Se–Se, Se–Ag, and Ag–Ag as a function of composition are determined from the radial distribution function. The experimental data are contrasted with a structure proposed for the glass. The fundamental structural unit of the glass is the Ge–Se4/2 tetrahedra. The present results are also compared with other authors.