Nanoscale control of exchange bias with BiFeO 3 thin films

Publication Type:

Journal Article

Authors:

L.W. Martin; Y.-H. Chu; M.B. Holcomb; M. Huijben; P. Yu; S.-J. Han; D. Lee; S.X. Wang; Ramamoorthy Ramesh

Source:

Nano Letters, Volume 8, Number 7, p.2050-2055 (2008)

Keywords:

Cobalt, Coercive fields, Coercive force, Crystals, Dichroism, Domain structures, Domain walls, exchange bias, Exchange enhancements, Ferroelectric domains, Ferroelectric materials, ferroelectricity, heterostructures, hysteresis, Large shifts, Magnetic domains, Magnetic thin films, multiferroic, Nano-scale, Nanoscale controls, nanostructured materials, Piezoresponse force microscopies, Semiconducting bismuth compounds, X ray crystallography, X-ray magnetic circular dichroisms

Abstract:

We demonstrate a direct correlation between the domain structure of multiferroic BiFeO 3 thin films and exchange bias of Co 0.9Fe 0.1/BiFeO 3 heterostructures. Two distinct types of interactions - an enhancement of the coercive field (exchange enhancement) and an enhancement of the coercive field combined with large shifts of the hysteresis loop (exchange bias) - have been observed in these heterostructures, which depend directly on the type and crystallography of the nanoscale (∼2 nm) domain walls in the BiFeO 3 film. We show that the magnitude of the exchange bias interaction scales with the length of 109° ferroelectric domain walls in the BiFeO 3 thin films which have been probed via piezoresponse force microscopy and X-ray magnetic circular dichroism. © 2008 American Chemical Society.

Notes:

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