Magnetic and electronic structure of the film-stabilized Mott insulator BaCrO${}_3$

We have synthesized and characterized laser-deposited film samples of perovskite BaCrO${}_3$, a missing member of the perovskite-chromate family. The BaCrO${}_3$ films have a substantially larger lattice constant than other chromates, are insulating, and exhibit weak ferromagnetism. Employing first-principles density functional theory calculations, we attribute such weak ferromagnetism to a canted $C$-type antiferromagnetic spin order. Additionally, comparison with the other sister compounds CaCrO${}_3$ and SrCrO${}_3$ suggests an anomalous Mott transition where magnetism is independent of whether the compound is metallic or insulating.