Raman spectra and athermal laser annealing ofGe(SxSe1−x

We have measured and interpreted the Raman spectra of bulk $\mathrm{Ge}{({\mathrm{S}}_{x}{\mathrm{Se}}_{1\ensuremath{-}x})}_{2}$ glasses for compositions in the range $0\ensuremath{\le}x\ensuremath{\le}0.25$, both at low power levels and at sufficiently high power levels to induce thermally reversible (at $T\ensuremath{\lesssim}\frac{{T}_{g}}{2}$) athermal microcrystallization. Substitution of Se by S in ${\mathrm{G}\mathrm{e}({\mathrm{Se}}_{1/2})}_{4}$ tetrahedra produced narrow satellites to the narrow ${A}_{1}$ symmetric breathing mode which are easily resolved. The splittings of these satellites are compared to those of the corresponding molecular lines of $\mathrm{Ge}{\mathrm{Cl}}_{n}{\mathrm{Br}}_{4\ensuremath{-}n}$ and are the basis for the molecular models discussed in the accompanying paper of Aronovitz et al. Athermal microcrystallization is achieved near liquid-nitrogen temperature. Addition of S up to $x=0.25$ is found to inhibit but not prevent thermal revitrification at room temperature ${T}_{r}\ensuremath{\sim}\frac{{T}_{g}}{2}$ on a time scale of hours.