Large zero-field cooled exchange bias in Ba1+δMn8O16 nanoribbons

Abstract

A large zero-field cooled exchange bias was obtained in single-crystal Ba1+δMn8O16 nanoribbons. Magnetization measurements indicate the coexistence of ferromagnetism and spin glass-like behavior in antiferromagnetic Ba1+δMn8O16 nanoribbons, which gives rise to a path-dependent exchange bias below the spin freezing temperature. Depending on the sign of the starting field [either positive (p) or negative (n)] as well as the maximum measurement field for the loop trace, the exchange bias (HE) varies significantly with |−HEp|>|+HEn|. HE has a monotonic decrease when increasing the maximum measurement field, |Hmmax|, to 3–6T. All features are attributed to the superexchange coupling between the ferromagnetic phase and the canted antiferromagnetic matrix via spin glass-like interface.