SÍNTESE E CARACTERIZAÇÃO DOS VIDROS TELURETOS DO SISTEMA (20-x) Li2O-80TeO2-xTiO2

Abstract

Glasses of the system (20-x)Li2O-80TeO2-xTiO2 were obtained from the traditional method of melting-quenching using electric furnace. For the study of crystallization mechanism, glasses with TiO2 composition x=0, 5 and 10 mol% were prepared and submitted to thermal treatment with temperature ranging from 310 °C up to 480 °C. DSC experiments were performed on different size particle samples with heating rate varying between 2.5 Kmin-1 and 10 Kmin-1. X-ray diffration peaks of TeO2 crystallites was identified in all of annealed matrices. On the other hand, adding to TeO2 phase the glass matrices with TiO2 shown TiTe3O8 phase in their XRD spectra. Infrared absorption data shown that this technique is suitable to monitoring the growth of TeO2 and TiTe3O8 phases into annealed tellurite glass matrices. Finally, combined DSC and XRD results obtained in the present work suggest that the crystallization can be essentially attributed to a distinct phase transformation identified as TeO2 and TiTe3O8 crystallites. DISSERTAÇÃO DEFENDIDA NA UNIVERSIDADE ESTADUAL PAULISTA (UNESP) "JÚLIO DE MESQUITA FILHO" FACULDADE DE ENGENHARIA – CAMPUS DE ILHA SOLTEIRA-SP