Perovskite BaCrO$_{3}$: completing a materials system with an anomalous Mott transition*

Perovskite BaCrO$_{3}$ cannot be stabilized in bulk but we have synthesized this compound as a film. BaCrO$_{3}$ films have a substantially larger lattice constant than other chromates, are insulating, and exhibit weak ferromagnetism likely associated with canted antiferromagnetism. Comparison with the sister compounds CaCrO$_{3}$ and SrCrO$_{3}$ suggests an anomalous Mott transition caused by lattice expansion where magnetism is independent of whether the compound is metallic or insulating.