Extended-range order in glasses [electronic resource].
- Arlington, Va. : National Science Foundation (U.S.), 1992.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 12 pages : digital, PDF file
- Additional Creators:
- Argonne National Laboratory
National Science Foundation (U.S.)
United States. Department of Energy. Office of Scientific and Technical Information
- The origin of intermediate-range order (IRO) in glasses remains one of the outstanding problems in condensed matter physics since indirect early evidence for its manifestation was seen in the Raman spectra of some glasses. The most general and persistent evidence of IRO, however, is the first sharp diffraction peak (FSDP), the feature observed at low wave-vector in the average structure factor S(Q) of many systems, including oxide, silicate and chalcogenide glasses and complex liquids. The FSDP is characterized by the fact that product of its wave vector Q₁ and the nearest-neighbor distance r₁ lies in the range 2.2--2.8, implying correlation lengths of the order of 2.5 r₁. The origin of the FSDP is controversial: it has been variously attributed to the presence of layer-like structures in the glass, to random packing of appropriate structural motifs, and to chemical ordering of voids and cations. Regardless of its origins, the FSDP clearly represents correlation lengths greater than those associated with the nominal building blocks of oxide and chalcogenide glasses. In this Letter, the authors report unambiguous evidence of structure extending well beyond the correlation length typical of the FSDP, based on recent neutron and anomalous x-ray scattering experiments on rubidium germanae glasses. They show that this structure is related to chemical ordering of the metal atoms and associated topological ordering of the oxygens.
- Published through SciTech Connect.
": Grant DMR-90-01704"
Price, D.L.; Howells, W.S.; Ellison, A.G.J.; Saboungi, M.L.; Egami, T.; Hu, R.Z.
- Type of Report and Period Covered Note:
- Topical; 11/01/1992 - 11/01/1992
- Funding Information:
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