Mechanosynthesis of disordered rock salt structures: thermodynamic and kinetic considerations

Oxide phases with a cation-disordered, cubic rock salt structure that can be prepared by mechanosynthesis include Li2TiO3, Li2MnO3, Li3NbO4, and a new polymorph of LiAlO2. They are all metastable and transform irreversibly to thermodynamically stable ordered structures on heating. Li2TiO3, Li2MnO3, and Li3NbO4 form cubic solid solutions by doping with LiF; depending on the composition, they may be stable or metastable thermodynamically. Factors that control the thermodynamic and kinetic stability of phases and their synthesis conditions are reviewed.