Local Structure of Si-Al-Ca-Na-O Glasses from Coupled Neutron and X-ray Total Scattering Data
Articolo
Data di Pubblicazione:
2012
Citazione:
Local Structure of Si-Al-Ca-Na-O Glasses from Coupled Neutron and X-ray Total Scattering Data / A. Bernasconi, M. Dapiaggi, A. Pavese, D.T. Bowron, S. Imberti. - In: JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL. - ISSN 1520-6106. - 116:43(2012), pp. 13114-13123.
Abstract:
Amorphous materials became significantly important and more widely
studied during the last few decades, due the their increasingly
widespread applications in materials science and technology. Their local
structure seems to have a very strong bond with those properties: in
this paper, the local structure of Si-Al-Ca-Na-O glasses is studied by
means of total scattering. EPSR simulations, coupling neutron, and X-ray
data have been used to study glass samples (as a function of
composition), with a composition close to the one used in their
technological applications (ceramic glazes), providing a consistent
structural model. The disordered structure of these materials has been
evaluated in terms of network-forming/modifier elements. The
network-forming elements (silicon and aluminum) show coordination
numbers and bond angles that are consistent with a tetrahedral
arrangement. In contrast, network-modifying elements (Ca and Na, whose
content is different in all samples) depolymerize the network,
increasing the number of nonbridging oxygens. This structural
information is required to rationalize many important technological
properties of these materials, such as the glass transition temperatures
and thermal expansion, that control their efficiency as glazes.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
A. Bernasconi, M. Dapiaggi, A. Pavese, D.T. Bowron, S. Imberti
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