Observation of a Continuous Random Network Structure in GexSe100鈥?i>x Glasses: Results from High-Resolution 77Se MATPASS/CPMG NMR Spectroscopy

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• 作者：Derrick C. Kaseman ; Ivan Hung ; Zhehong Gan ; Sabyasachi Sen
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：January 24, 2013
• 年：2013
• 卷：117
• 期：3
• 页码：949-954
• 全文大小：345K
• 年卷期：v.117,no.3(January 24, 2013)
• ISSN：1520-5207

文摘

The coordination environments of Se atoms in binary Ge_xSe_100鈥?i>x glasses with 5 鈮?x 鈮?30 are investigated using a novel, two-dimensional ⁷⁷Se nuclear magnetic resonance (NMR) spectroscopic technique. The high-resolution isotropic ⁷⁷Se NMR spectra allow for the identification of up to four distinct Se sites in these glasses. The chemical shift tensor parameters for these sites offer unique insights into their local site symmetries and nearest- and next-nearest-neighbor coordination environments. The structural results, when taken together, provide direct evidence in favor of the existence of a randomly connected network of GeSe₄ tetrahedra and Se鈥揝e chain fragments in these glasses.