A containerless study of short-range order in high-temperature Fe–Si–Al–Ca–Mg–Cr–Cu–Ni oxide systems

The short-range order of a composite Fe–Si–Al–Ca–Mg–Cr–Cu–Ni oxide system in the liquid state (1500 °C) during aerodynamic levitation was studied by high-energy X-ray diffraction and subsequent Reverse Monte Carlo simulations. Structural analysis of the resulting supercells revealed the presence a sialate network consisting of SiO4 tetrahedra chains terminated by AlO4 units. Network modifying Fe and Mg atoms within the sialate cavities provided the necessary charge neutrality. Ca atoms were largely uncoordinated, while Cr, although not assuming a network forming role, maintained a 4-fold coordination, effectively reducing the amount of bridging O atoms in the melt. Due to their low concentration, the Cu and Ni species were not included in the analysis. The stereochemistry of the most probable atomic cluster, characteristic of short-range coordination, was derived.