Room temperature exchange bias in BiFeO3 / Co-Fe bilayers

Abstract

Thin highly epitaxial BiFeO${}_3$ films were prepared on SrTiO${}_3$ (100) substrates by reactive magnetron co-sputtering. Detailed MOKE measurements on BiFeO${}_3$/Co-Fe bilayers were performed to investigate the exchange bias as a function of the films thicknesses and Co-Fe stoichiometries. We found a maximum exchange bias of H${}_{\mathrm{eb}}$=92 Oe and a coercive field of H${}_{\mathrm{c}}$=89 Oe for a 12.5 nm thick BiFeO${}_3$ film with a 2 nm thick Co layer. The unidirectional anisotropy is clearly visible in in-plane rotational MOKE measurements. AMR measurements reveal a strongly increasing coercivity with decreasing temperature, but no significant change in the exchange bias field.

References in corpus (2)

• Tunnel magnetoresistance and robust room temperature exchange bias with multiferroic BiFeO3 epitaxial thin films
• Large exchange bias in polycrystalline MnN/CoFe bilayers at room temperature