Control of Positive and Negative Magnetoresistance in Iron Oxide-Iron Nanocomposite Thin Films for Tunable Magnetoelectric Nanodevices
Nichterwitz M, Honnali S, Zehner J, Schneider S, Pohl D, Schiemenz S, Goennenwein STB, Nielsch K, Leistner K (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 2
Pages Range: 2543-2549
Journal Issue: 8
Abstract
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.
Involved external institutions
Technische Universität Dresden
Germany (DE)
Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden
Germany (DE)
Germany (DE)
Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden
Germany (DE)
How to cite
APA:
Nichterwitz, M., Honnali, S., Zehner, J., Schneider, S., Pohl, D., Schiemenz, S.,... Leistner, K. (2020). Control of Positive and Negative Magnetoresistance in Iron Oxide-Iron Nanocomposite Thin Films for Tunable Magnetoelectric Nanodevices. ACS Applied Electronic Materials, 2(8), 2543-2549. https://doi.org/10.1021/acsaelm.0c00448
MLA:
Nichterwitz, Martin, et al. "Control of Positive and Negative Magnetoresistance in Iron Oxide-Iron Nanocomposite Thin Films for Tunable Magnetoelectric Nanodevices." ACS Applied Electronic Materials 2.8 (2020): 2543-2549.
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