| Abstract Scope |
Within the Na2O, Fe2O3, SiO2 ternary phase diagram, a unique isochemically crystalizing glass forms with the composition Na5FeSi4O12 also known as the 5.1.8 phase. This glass, and Na5MSi4O12-type silicates generally, are of academic interest as a model system for geologic, and radioactive waste management applications, as well as Na-ion conductors for next generation batteries. This study examines the role of substitutions of Al in the Fe site of Na5FeSi4O12 glasses and crystals by synthesizing a glass series with differing amounts Al2O3 and Fe2O3 while retaining the 5.1.8 stoichiometry. The crystals will be characterized by X-ray Diffraction and Raman spectroscopy. Further, the glass and structures will be probed to illuminate the role played by Fe and Al on affecting structure, properties, and thermodynamics of silicate melts and minerals. Ultimately, this research program strives to elucidate the contribution of Fe and Al towards configurational entropy in silicate minerals and glasses. |