Highly cyclable voltage control of magnetism in cobalt ferrite nanopillars for memory and neuromorphic applications

• Published in: APL materials Vol. 11; no. 5; pp. 051105 - 051105-10
• Main Authors: de h-Óra, Muireann, Nicolenco, Aliona, Monalisha, P., Maity, Tuhin, Zhu, Bonan, Lee, Shinbuhm, Sun, Zhuotong, Sort, Jordi, MacManus-Driscoll, Judith
• Format: Journal Article
• Language: English
• Published: AIP Publishing LLC 01-05-2023
• ISSN: 2166-532X; 2166-532X
• DOI: 10.1063/5.0147665

Tuning the properties of magnetic materials by voltage-driven ion migration (magneto-ionics) gives potential for energy-efficient, non-volatile magnetic memory and neuromorphic computing. Here, we report large changes in the magnetic moment at saturation (mS) and coercivity (HC), of 34% and 78%, respectively, in an array of CoFe2O4 (CFO) epitaxial nanopillar electrodes (∼50 nm diameter, ∼70 nm pitch, and 90 nm in height) with an applied voltage of −10 V in a liquid electrolyte cell. Furthermore, a magneto-ionic response faster than 3 s and endurance >2000 cycles are demonstrated. The response time is faster than for other magneto-ionic films of similar thickness, and cyclability is around two orders of magnitude higher than for other oxygen magneto-ionic systems. Using a range of characterization techniques, magnetic switching is shown to arise from the modulation of oxygen content in the CFO. Also, the highly cyclable, self-assembled nanopillar structures were demonstrated to emulate various synaptic behaviors, exhibiting non-volatile, multilevel magnetic states for analog computing and high-density storage. Overall, CFO nanopillar arrays offer the potential to be used as interconnected synapses for advanced neuromorphic computing applications.