Effect of CaO partial substituted by BaO on structure of aluminotitanate melts by molecular dynamics simulation

Abstract

The effect of CaO partial substituted by BaO on the microstructure of aluminotitanate melts by molecular dynamics (MD) and spectroscopy, especially the alteration of Al2O3 and TiO2 amphoteric behavior. The MD simulation results indicated that as the BaO content increased from 15 to 18 wt%, TiO2 transformed into [TiO6] octahedral and Al2O3 transformed to alkaline. The BaO content increased above 18 wt%, and the continuous insufficient supply of cations further promoted the transition of TiO2 to low coordination reducing the potential connection between the common edges. The dissociation of Ba2+ from BaO supported the transformation of small molecular units into macromolecular units and improved the degree of polymerization of the melt. Raman spectra showed that when BaO concentration grew, the complexity of the [AlOx] polyhedra increased, promoting the transformation of TiO2 to alkaline [TiO6] first and then to acidic [TiO5], which is consistent with the results of the MD.