https://repositorio.ufba.br/handle/ufba/573
Tipo: | Artigo de Periódico Artigo de Periódico |
Título: | Intermediate-range order of alkali disilicate glasses and its relation to the devitrification mechanism |
Autor(es): | Longstaffe, James Werner-Zwanziger, Ulrike Schneider, Jose Fabian Nascimento, Marcio Luis Ferreira Zanotto, Edgar Dutra Zwanziger, Joseph |
Autor(es): | 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 |
Palavras-chave: | Vidro NMR Cristalização Crescimento de Cristais Viscosidade Nucleação |
URI: | http://www.repositorio.ufba.br/ri/handle/ufba/573 |
Data do documento: | 2008 |
Aparece nas coleções: | Artigo Publicado em Periódico (PEI) |
Arquivo | Descrição | Tamanho | Formato | |
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IntermediateRangeOrderAlkaliDisilicate-JPC112-Nascimento.pdf | 230,4 kB | Adobe PDF | Visualizar/Abrir |
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