A combined Se-77 NMR and Raman spectroscopic study of the structure of GexSe1-x glasses: Towards a self consistent structural model

作者：Edwards Trenton G; Sen Sabyasachi^*; Gjersing Erica L

来源：Journal of Non-Crystalline Solids, 2012, 358(3): 609-614.

DOI：10.1016/j.jnoncrysol.2011.11.008

• Germanium selenide glass
• Chalcogenide glass
• Structure
• 77Se NMR spectroscopy
• Raman spectroscopy

The short-range structures of stoichiometric and Se-deficient binary GexSe100-x glasses with 42 >= x >= 33.33 have been investigated using a combination of Raman and Se-77 Car-Purcell-Meiboom-Gill (CPMG) spikelet nuclear magnetic resonance (NMR) spectroscopy. When taken together, these spectroscopic results allow for self-consistent assignment of average Se-77 NMR isotropic chemical shifts to Se atoms in various coordination environments in GexSe100-x glasses. Analysis of the compositional variation of the relative concentrations of these Se environments indicates considerable violation of chemical order in the nearest-neighbor coordination environments of the constituent atoms in the stoichiometric Ge33.33Se66.67 glass. On the other hand, the presence of a random distribution of Ge-Ge bonds can be inferred in the Se-deficient glasses. Simulations of the previously published Se-77 NMR line shapes of Se-excess glasses on the basis of the revised structural assignments of Se-77 NMR chemical shifts obtained in this study conclusively indicate that the structure of these glasses is intermediate between a randomly connected and a fully clustered network of GeSe4 tetrahedra and Se chains.

• 出版日期2012-2-1