Voltage control of magnetism in metal oxide/metal nanoislands and nanostripes*

Voltage control of magnetism by ionic approaches presents a promising pathway to low-power magnetic devices. Up to now, magneto-ionic manipulation has been reported mainly for ultrathin films and nanoporous structures.[1-3] Since the mechanism is based on interfacial charge transfer, the morphology may be key to the magneto-ionic efficiency.
We investigate the influence of morphology on magneto-ionic changes during electrolytic gating of FeO_x/Fe nanostructures. In FeO_x/Fe nanoislands [4], the magneto-ionic changes are enhanced compared to continuous films and close to ON/OFF switching of magnetization is achieved.[5] The results are explained mainly by the higher surface/volume ratio of the nanoislands. Further, we investigate the transfer of magneto-ionic effects from extended thin film to nanostripe geometry. We present initial results on voltage-controlled magnetoresistance in FeO_x/Fe stripes probed via in situ magneto-transport measurements.
[1] Gilbert et al., Nat. Commun., 2016, 7, 12264
[2] Quintana et al., Small, 2018, 14, 1704396
[3] Duschek et al., APL Mater.,2016, 4, 032301
[4] Leistner et al., Nanoscale, 2017, 9, 5315
[5] Duschek et al., J. Mater. Chem. C, 2018, 6, 8411