Selenium Chain Length Distribution in GexSe100–x Glasses: Insights from 77Se NMR Spectroscopy and Quantum Chemical Calculations

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• 作者：Derrick C. Kaseman ; Karina Moreira Oliveira ; Teresa Palazzo ; Sabyasachi Sen
• 刊名：Journal of Physical Chemistry B
• 出版年：2016
• 出版时间：May 19, 2016
• 年：2016
• 卷：120
• 期：19
• 页码：4513-4521
• 全文大小：413K
• 年卷期：0
• ISSN：1520-5207

文摘

The statistics of selenium chain length distribution in Ge_xSe_100–x glasses with 5 ≤ x ≤ 20 are investigated using a combination of high-resolution, two-dimensional ⁷⁷Se nuclear magnetic resonance (NMR) spectroscopy and quantum chemical calculations. This combined approach allows for the distinction of various selenium chain environments on the basis of subtle but systematic effects of next-nearest neighbors of Se atoms in −Se–Se–Se– linkages on the ⁷⁷Se chemical shift tensor parameters. Simulation of the experimental ⁷⁷Se NMR spectral line shapes indicates that Se chain speciation in these chalcogenide glasses follows the Flory–Schulz distribution, originally developed for organic chain polymers.