NUK - logo
E-viri
Celotno besedilo
Recenzirano
  • In situ evolution of Ni env...
    Dugué, A.; Dymshits, O.; Cormier, L.; Cochain, B.; Lelong, G.; Zhilin, A.; Belin, S.

    The Journal of physics and chemistry of solids, 03/2015, Letnik: 78
    Journal Article

    The evolution of Ni2+ environment has been systematically investigated using optical and in situ X-ray absorption spectroscopy (XAS) to determine the influence of nucleating agents (TiO2 and/or ZrO2) during the formation of spinel in magnesium aluminosilicate glass–ceramics. The results were complemented by in situ X-ray diffraction data. According to XAS and optical spectroscopy, the nature of nucleating agents does not modify significantly the Ni environment in initial glasses. However, it has a relatively strong influence in the observed crystallization sequence. Ni2+ ions do not enter the Zr-containing crystalline phase of ZrO2 or ZrTiO4 but a Ni2+ coordination change from the fivefold coordinated sites, with a small amount of tetrahedral sites in parent glasses, to 6Ni2+ and 4Ni2+ sites in spinel (in glasses nucleated by ZrO2 and/or TiO2) or in β-quartz solid solutions (in glasses nucleated by ZrO2) has been found.