Passivation of the La2NiMnO6 double perovskite to hydroxylation by excess nickel, and the fate of the hydroxylated surface upon heating

- Lanthanum nickel manganese oxide formed a double perovskite, LaNi0.5Mn0.5O3.
- LaNi0.75Mn0.25O3 phase separated into LaNi0.5Mn0.5O3, NiO and LaNiO3.
- Stoichiometric LaNi0.5Mn0.5O3 formed an extensively hydroxylated overlayer.
- Heating formed an La2O3 overlayer and did not regenerate the perovskite.
- Excess nickel prevented extensive hydroxylation.