Crystallization, mechanical, and optical properties of transparent, nanocrystalline gahnite glass-ceramics

Autor(es)

Molla, Atiar R. ; Rodrigues, Alisson M. ; Singh, Shiv Prakash ; Lancelotti, Ricardo Felipe ; Zanotto, Edgar D. ; Rodrigues, Ana C. M. ; Dousti, Mohammad Reza ; de Camargo, Andrea S. S. ; Magon, Claudio Jose ; Almeida Silva, Igor D'Anciaes

• Tipo de documento: Artigo Científico
• Fonte: Journal of the American Ceramic Society; v. 100, n. 5, p. 1963-1975, MAY 2017.
• Citações Web of Science: 9

Resumo

This paper describes the preparation of a transparent glass-ceramic from the SiO2-K2O-ZnO-Al2O3-TiO2 system containing a single crystalline phase, gahnite (ZnAl2O4). TiO2 was used as a nucleating agent for the heat-induced precipitation of gahnite crystals of 5-10 nm. The evolution of the ZnAl2O4 spinel structure through the gradual formation of Al-O bonds was examined by infrared spectroscopy. The dark brown color of the transparent precursor glass and glass-ceramic was eliminated using CeO2. The increase in transparency of the CeO2-doped glass and glass-ceramics was demonstrated by UV-visible absorption spectroscopy. EPR measurements confirmed the presence of Ce3+ ions, indicating that CeO2 was effective in eliminating the brown color introduced by Ti3+ ions via oxidation to Ti+4. The hardness of the glass-ceramic was 30% higher than that of the as-prepared glasses. This work offers key guidelines to produce hard, transparent glass-ceramics which may be potential candidates for a variety of technological applications, such as armor and display panels. (AU)

• Processo FAPESP: 14/20865-9 - Síntese e propriedades de vitrocerâmicas contendo fase espinélio nanométrica para aplicações em sistemas de proteção e fotônicas
• Beneficiário: Ana Candida Martins Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 13/24064-8 - Estudos estruturais e fotofísicos de vidros fosfato de tungstênio dopados com íons terras raras e nanopartículas metálicas
• Beneficiário: Mohammad Reza Dousti
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/07793-6 - CEPIV - Centro de Ensino, Pesquisa e Inovação em Vidros
• Beneficiário: Edgar Dutra Zanotto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs