Evidence of spin reorientation transition below 150 K from magnetic force microscopy in a ferromagnetic BiFeO${}_3$ thin film

Abstract

We investigated the magnetic transitions in BiFeO${}_3$ at low temperature (5-300 K) and observed nearly 90${}^o$ rotation of magnetic domains (imaged by vertical magnetic force microscopy) across 150 K in an epitaxial thin film of thickness $\sim$36 nm. It offers a clear evidence of spin reorientation transition. It also corroborates the transition observed below $\sim$150 K in the zero-field-cooled and field-cooled magnetization versus temperature data. The field-driven 180${}^o$ domain switching at room temperature, on the other hand, signifies presence of ferromagnetism. Since bulk antiferromagnetic BiFeO${}_3$ does not exhibit such a transition, this observation in ferromagnetic thin film of BiFeO${}_3$ indicates a radical effect because of epitaxial strain. Density functional theory based first-principles calculations too reveal that combined in- and out-of-plane epitaxial strain induces magnetic transition from G- to C-type structure in BiFeO${}_3$.

12 pages, 9 figures, published in Phys. Rev. B

References in corpus (3)

• Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite
• Field-induced reorientation of helimagnetic order in Cu${}_2$OSeO${}_3$ probed by magnetic force microscopy
• Large structure-dependent room temperature exchange bias in self-assembled BiFeO3 nanoparticles