Please use this identifier to cite or link to this item:
metadata.dc.type: Artigo de Periódico
Artigo de Periódico
Title: Intermediate-range order of alkali disilicate glasses and its relation to the devitrification mechanism
Authors: Longstaffe, James
Werner-Zwanziger, Ulrike
Schneider, Jose Fabian
Nascimento, Marcio Luis Ferreira
Zanotto, Edgar Dutra
Zwanziger, Joseph
Abstract: There are two general mechanisms of devitrification in glass: heterogeneous nucleation of crystals from surfaces and impurities, and homogeneous nucleation from the volume. It is thought that structural similarities between glass and crystal at the intermediate-range level influence the mechanism followed, however there are few scarse experimental studies to test this hypothesis. In this paper solid-state nuclear magnetic resonance spectroscopy is used to probe intermediate-range order in sodium and lithium disilicate glasses through measurement of the second moment of the distribution of dipolar couplings. These two glasses undergo heterogeneous and homogeneous nucleation respectively. The second moments measured for the lithium glass closely follow the trend established by the layered structures of the isochemical crystalline phases while the same measurements for the sodium glass do not. This observation supports the hypothesis that glasses capable of homogeneous nucleation are structurally more similar to the resulting crystalline phases than those glasses that exhibit only heterogeneous nucleation
Keywords: Vidro
Crescimento de Cristais
Issue Date: 1-Feb-2008
Appears in Collections:Artigos Publicados em Periódicos (PEI)

Files in This Item:
File Description SizeFormat 
IntermediateRangeOrderAlkaliDisilicate-JPC112-Nascimento.pdf230,4 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.