Mechanism of crystallization of Co-cordierites from stoichiometric powdered glasses

The influence of cobalt, as a divalent cation, on the crystallization behaviour of the cordierite based glasses was studied. Powdered glass specimens of stoichiometric composition 2MO 2Al2O3 5SiO2 (M=Co and/or Mg) were obtained and thermally treated at several temperatures and times, and the sequenc...

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Detalles Bibliográficos
Autores: Villegas Broncano, María Ángeles, Alarcón, Javier
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2002
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/417928
Acceso en línea:http://hdl.handle.net/10261/417928
Access Level:acceso abierto
Palabra clave:Cordierite
Crystallization
Glass
Glass ceramics
Descripción
Sumario:The influence of cobalt, as a divalent cation, on the crystallization behaviour of the cordierite based glasses was studied. Powdered glass specimens of stoichiometric composition 2MO 2Al2O3 5SiO2 (M=Co and/or Mg) were obtained and thermally treated at several temperatures and times, and the sequence of crystallization and their microstructural evolution were analysed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Results on the crystallization sequence showed that the steps in the crystallization path are independent of the nature of the divalent cation. The first crystalline phase detected displayed the μ-cordierite structure, i.e. a solid solution with β-quartz structure. After further thermal treatment a phase with α-cordierite structure was formed. Cobalt μ- and α-cordierites were further characterized by infrared (IR) and UV–vis diffuse reflectance spectroscopies. The final morphology of cobalt-containing hexagonal cordierites depended on the densification degree of the precursor glass.