Member, The American Ceramic Society.
Evolution of the Ni2+ Environment During the Formation of a MgO–Al2O3–SiO2 Glass-Ceramic: A Combined XRD and Diffuse Reflectance Spectroscopy Approach
Article first published online: 12 SEP 2012
© 2012 The American Ceramic Society
Journal of the American Ceramic Society
Volume 95, Issue 11, pages 3483–3489, November 2012
How to Cite
Dugué, A., Cormier, L., Dargaud, O., Galoisy, L., Calas, G. (2012), Evolution of the Ni2+ Environment During the Formation of a MgO–Al2O3–SiO2 Glass-Ceramic: A Combined XRD and Diffuse Reflectance Spectroscopy Approach. Journal of the American Ceramic Society, 95: 3483–3489. doi: 10.1111/j.1551-2916.2012.05421.x
- Issue published online: 2 NOV 2012
- Article first published online: 12 SEP 2012
- Manuscript Accepted: 24 JUL 2012
- Manuscript Received: 20 JAN 2012
The effect of the addition of NiO on the crystallization mechanisms has been studied for SiO2–Al2O3–MgO glass-ceramics. A detailed Rietveld analysis has been made to determine the chemical composition and the cation distribution in the spinel phase and the evolution of Ni2+ coordination site using diffuse reflectance spectroscopy. Powder X-ray diffraction (XRD) results show the formation of β-quartz and spinel and the nickel fraction in the spinel phase decreasing as the plateau temperature increases. The determination of cation distribution in spinel using XRD reveals a preference of Ni2+ and Al3+ for octahedral sites and an increasing proportion of Ni2+ in tetrahedral sites for heat treatments at high temperature (1100°C–1200°C). Diffuse reflectance spectroscopy shows that Ni2+ is mainly fivefold coordinated in the starting glass, playing an important role in the crystallization of the spinel phase and it confirms the presence of tetrahedral and octahedral Ni2+ in the glass-ceramics. The combination of these two techniques also indicates a chemical heterogeneity of spinel crystals with Ni2+-rich and Mg2+-rich zones.