title: In situ observation of reversible nanomagnetic switching induced by electric fields.
abstract: We report direct observation of controlled and reversible switching of magnetic domains using static (dc) electric fields applied in situ during Lorentz microscopy. The switching is realized through electromechanical coupling in thin film Fe(0.7)Ga(0.3)/BaTiO(3) bilayer structures mechanically released from the growth substrate. The domain wall motion is observed dynamically, allowing the direct association of local magnetic ordering throughout a range of applied electric fields. During application of approximately 7-11 MV/m electric fields to the piezoelectric BaTiO(3) film, local magnetic domains rearrange in the ferromagnetic Fe(0.7)Ga(0.3) layer due to the transfer of strain from the BaTiO(3) film. A simulation based on micromagnetic modeling shows a magnetostrictive anisotropy of 25 kPa induced in the Fe(0.7)Ga(0.3) due to the strain. This electric-field-dependent uniaxial anisotropy is proposed as a possible mechanism to control the coercive field during operation of an integrated magnetoelectric memory node.
authors.affiliation: Naval Research Laboratory, Washington, DC 20375, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Brintlinger
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Lim
authors.forename: Kamal H
authors.initials: KH
authors.lastname: Baloch
authors.forename: Paris
authors.initials: P
authors.lastname: Alexander
authors.forename: Yi
authors.initials: Y
authors.lastname: Qi
authors.forename: John
authors.initials: J
authors.lastname: Barry
authors.forename: John
authors.initials: J
authors.lastname: Melngailis
authors.forename: Lourdes
authors.initials: L
authors.lastname: Salamanca-Riba
authors.forename: I
authors.initials: I
authors.lastname: Takeuchi
authors.forename: John
authors.initials: J
authors.lastname: Cumings
mesh_terms: D004574:Electromagnetic Fields; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*