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

The effect of CaO partial substituted by BaO on the microstructure of aluminotitanate melts by molecular dynamics (MD) and spectroscopy, especially the alteration of Al ₂O ₃ and TiO ₂ amphoteric behavior. The MD simulation results indicated that as the BaO content increased from 15 to 18 wt%, TiO ₂ transformed into [TiO ₆] octahedral and Al ₂O ₃ transformed to alkaline. The BaO content increased above 18 wt%, and the continuous insufficient supply of cations further promoted the transition of TiO ₂ to low coordination reducing the potential connection between the common edges. The dissociation of Ba ²⁺ 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 [AlO _x] polyhedra increased, promoting the transformation of TiO ₂ to alkaline [TiO ₆] first and then to acidic [TiO ₅], which is consistent with the results of the MD.