Precise x-ray diffraction measurements using high-energy x rays of synchrotron radiation and systematic Raman scattering measurements were carried out for GexS100−x (10 ⩽ x ⩽ 40) network glasses. The structural models of the network glasses were proposed based on the results. In the stoichiometric composition Ge33S67, GeS4 tetrahedral units are connected forming either corner-sharing or edge-sharing structures. In the S-rich glasses, S atoms are inserted between two neighboring GeS4 tetrahedra, resulting in a flexible floppy network. In a much more S-rich region, some S8 ring molecules are isolated from the network, and assemble to form a crystal in nanoscopic scale. In this respect, Ge10S90 samples are regarded as crystallized glasses. In the Ge-rich region, the GeS4 tetrahedra are connected with bridging Ge atoms. The connection makes a new rigid network. The bridging Ge-S bond is weaker than the intratetrahedron bond, and this leads to drastic changes in the optical properties.
Copyright (2019) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in:
Y. Sakaguchi, T. Hanashima, K. Ohara, Al-Amin A. Simon, & M. Mitkova. (2019). Structural Transformation in GexS100−x (10 ≤ x ≤ 40) Network Glasses: Structural Varieties in Short-Range, Medium-Range, and Nanoscopic Scale. Physical Review Materials, 3(3), 035601. doi: 10.1103/PhysRevMaterials.3.035601
Sakaguchi, Y.; Hanashima, T.; Ohara, K.; Simon, Al-Amin A.; and Mitkova, M.. (2019). "Structural Transformation in GexS100−x (10 ≤ x ≤ 40) Network Glasses: Structural Varieties in Short-Range, Medium-Range, and Nanoscopic Scale". Physical Review Materials, 3(3), 035601-1 - 035601-18. http://dx.doi.org/10.1103/PhysRevMaterials.3.035601
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