Anisotropic bimodal distribution of blocking temperature with multiferroic BiFeO3 epitaxial thin films

C. K. Safeer, M. Chamfrault, J. Allibe, C. Carretero, C. Deranlot, E. Jacquet, J.-F. Jacquot, M. Bibes, A. Barthélémy, B. Dieny, H. Béa, V. Baltz
2012 Applied Physics Letters  
Controlling BiFeO 3 (BFO)/ferromagnet (FM) interfacial coupling appears crucial for electrical control of spintronic devices using this multiferroic. Here, we analyse the magnetic behaviour of exchange-biased epitaxial-BiFeO 3 /FM bilayers with in-plane or out-of-plane magnetic anisotropies. We report bimodal distributions of blocking temperatures similar to those of polycrystalline-antiferromagnet (AF)/FM bilayers. The high-temperature contribution depends on the FM anisotropy direction and is
more » ... likely related to thermally activated depinning of domain walls in the BiFeO 3 single crystal film as opposed to thermally activated reversal of spins in AF grains for polycrystalline AF. In contrast, the low-temperature contribution weakly depends on the anisotropy direction, consistent with a spin-glass origin.
doi:10.1063/1.3684812 fatcat:hungzbhtybhhzdc67jwdl56btu