Control of positive and negative magnetoresistance in iron oxide−iron nanocomposite thin films for tunable magnetoelectric nanodevices
Nichterwitz, Martin (Technische Universität Dresden. Physical Chemistry (Germany))
Honnali, Shashank (Leibniz Institute for Solid State and Materials Research Dresden (Germany))
Zehner, Jonas (Technische Universität Dresden. Institute of Material Science (Germany))
Schneider, Sebastian (Leibniz Institute for Solid State and Materials Research Dresden (Germany))
Pohl, Darius (Dresden Center for Nanoanalysis (DCN)/Center for Advancing Electronics Dresden (Germany))
Schiemenz, Sandra (Leibniz Institute for Solid State and Materials Research Dresden (Germany))
Goennenwein, Sebastian T. B. (Technische Universität Dresden. Institut für Festkörper- und Materialphysik (Germany))
Nielsch, Kornelius (Technische Universität Dresden. Institute of Material Science (Germany))
Leistner, Karin (Technische Universität Dresden. Institute of Material Science (Germany))

Data:	2020
Resum:	The perspective of energy-efficient and tunable functional magnetic nanostructures has triggered research efforts in the fields of voltage control of magnetism and spintronics. We investigate the magnetotransport properties of nanocomposite iron oxide/iron thin films with a nominal iron thickness of 5-50 nm and find a positive magnetoresistance at small thicknesses. The highest magnetoresistance was found for 30 nm Fe with +1. 1% at 3 T. This anomalous behavior is attributed to the presence of Fe3O4-Fe nanocomposite regions due to grain boundary oxidation. At the Fe3O4/Fe interfaces, spin-polarized electrons in the magnetite can be scattered and reoriented. A crossover to negative magnetoresistance (−0. 11%) is achieved at a larger thickness (>40 nm) when interface scattering effects become negligible as more current flows through the iron layer. Electrolytic gating of this system induces voltage-triggered redox reactions in the Fe3O4 regions and thereby enables voltage-tuning of the magnetoresistance with the locally oxidized regions as the active tuning elements. In the low-magnetic-field region (<1 T), a crossover from positive to negative magnetoresistance is achieved by a voltage change of only 1. 72 V. At 3 T, a relative change of magnetoresistance about −45% during reduction was achieved for the 30 nm Fe sample. The present low-voltage approach signifies a step forward to practical and tunable room-temperature magnetoresistance-based nanodevices, which can boost the development of nanoscale and energy-efficient magnetic field sensors with high sensitivity, magnetic memories, and magnetoelectric devices in general.
Ajuts:	European Commission 861145
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Magnetoresistance ; Voltage control of magnetism ; Magneto-ionic control ; Magnetite ; Iron films
Publicat a:	ACS applied electronic materials, Vol. 2, Issue 8 (August 2020) , p. 2543-2549, ISSN 2637-6113

DOI: 10.1021/acsaelm.0c00448

Postprint 31 p, 789.9 KB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Grup de nanoenginyeria de materials, nanomagnetisme i nanomecànica (Gnm3)
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