The structure of sodium iron silicate glass - a multi-technique approach
UNSPECIFIED (1999) The structure of sodium iron silicate glass - a multi-technique approach. In: 18th International Congress of Glass, JUL 05-10, 1998, SAN FRANCISCO, CALIFORNIA.Full text not available from this repository.
Sodium iron silicate glasses of formula 0.3Na(2)O . xFe(2)O(3).(0.7-x)SiO2 (0.0 less than or equal to x less than or equal to 0.20) have been prepared by melt-quenching and their structures have been studied using X-ray photoelectron spectroscopy (XPS), neutron diffraction and Mossbauer spectroscopy. XPS of surfaces fractured in ultra-high vacuum showed the presence of both Fe2+ and Fe3+ in the glasses but the proportion of the smaller oxidation state is <20% for larger x. The O 1s spectrum can be fitted by bridging and non-bridging oxygen contributions but properties show that this description is inadequate and there are contributions from bridging oxygens, Si-O-Si, from non-bridging oxygens, Si-O Na+ and also directionally bonded Si-O-Fe. The neutron diffraction and Mossbauer data indicate that iron, irrespective of oxidation state, is 4-coordinated by oxygen. The Fe-O bond length decreases and the O-O bond length increases with increasing Fe2O3 content. Mossbauer spectroscopy confirms the predominance of the Fe3+ state in these glasses and indicates smaller Fe2+ concentrations than does XPS. possibly due to restructuring at the glass fracture surfaces examined in XPS, The effective Debye temperatures for Fe2+ and Fe3+ are 258 and 312 K, respectively, a consequence of the different M-O bond strengths of the two oxidation states. (C) 1999 Elsevier Science B.V. All rights reserved.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||T Technology > TP Chemical technology
T Technology > TA Engineering (General). Civil engineering (General)
|Journal or Publication Title:||JOURNAL OF NON-CRYSTALLINE SOLIDS|
|Publisher:||ELSEVIER SCIENCE BV|
|Number of Pages:||11|
|Page Range:||pp. 192-202|
|Title of Event:||18th International Congress of Glass|
|Location of Event:||SAN FRANCISCO, CALIFORNIA|
|Date(s) of Event:||JUL 05-10, 1998|
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