Voltage-gated ion transport as a means of manipulating magnetism electrically could enable ultralow-power memory, logic and sensor technologies. Earlier work made use of electric-field-driven O2− displacement to modulate magnetism in thin films by controlling interfacial or bulk oxidation states. However, elevated temperatures are required and chemical and structural changes lead to irreversibility and device degradation. Here we show reversible and non-destructive toggling of magnetic anisotropy at room temperature using a small gate voltage through H+ pumping in all-solid-state heterostructures. We achieve 90° magnetization switching by H+ insertion at a Co/GdOx interface, with no degradation in magnetic properties after >2,000 cycles. We then demonstrate reversible anisotropy gating by hydrogen loading in Pd/Co/Pd heterostructures, making metal–metal interfaces susceptible to voltage control. The hydrogen storage metals Pd and Pt are high spin–orbit coupling materials commonly used to generate perpendicular magnetic anisotropy, Dzyaloshinskii–Moriya interaction, and spin–orbit torques in ferromagnet/heavy-metal heterostructures. Thus, our work provides a platform for voltage-controlled spin–orbitronics.
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The data that support the findings of this study are available from the corresponding author upon reasonable request.
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This work was primarily supported by the National Science Foundation (NSF) through the Massachusetts Institute of Technology Materials Research Science and Engineering Center (MRSEC) under award number DMR-1419807. We acknowledge technical support from D. Bono. We also thank A. Grimaud for insights on the electrochemistry of water splitting. Work was performed using facilities in the MIT Microsystems Technology Laboratory and in the Center for Materials Science and Engineering, supported by the NSF MRSEC programme under award number DMR–1419807. This research used resources from the 23-ID-1 Coherent Soft X-ray Scattering beamline of the National Synchrotron Light Source II, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under contract number DE-SC0012704.
The author declares no competing interests.
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Tan, A.J., Huang, M., Avci, C.O. et al. Magneto-ionic control of magnetism using a solid-state proton pump. Nature Mater 18, 35–41 (2019). https://doi.org/10.1038/s41563-018-0211-5
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