Electrically Driven Exchange Bias via Solid State Magneto-Ionics

Published

August 4, 2021

Author(s)

Peyton Murray, Christopher Jensen, Alberto Quintana, Junwei Zhang, Xixiang Zhang, Alexander Grutter, Brian Kirby, Kai Liu

Abstract

Electrically induced ionic motion offers a new way to realize voltage-controlled magnetism, opening the door to a new generation of logic, sensor, and data storage technologies. Here, we demonstrate an effective approach to magneto-ionically and electrically tune exchange bias in Gd/Ni_1-xCo_xO thin films (x=0.50, 0.67), where neither of the layers alone is magnetic at room temperature. The Gd capping layer deposited onto antiferromagnetic Ni_1-xCo_xO initiates a solid-state redox reaction that reduces an interfacial region of the oxide to ferromagnetic NiCo. Exchange bias is established after field cooling, which can be enhanced by up to 35% after a voltage conditioning and subsequently reset with a second field cooling. These effects are caused by the presence of an interfacial magnetic NiCo layer, which further alloys with the Gd layer upon field cooling and voltage application, as confirmed by electron microscopy and polarized neutron reflectometry studies. These results highlight the viability of the solid-state magneto-ionic approach to achieve electric control of exchange bias, with potentials for energy-efficient magnetoionic devices.

Citation

Nano Letters

Pub Type

Journals

Keywords

magnetism

Citation

Murray, P. , Jensen, C. , Quintana, A. , Zhang, J. , Zhang, X. , Grutter, A. , Kirby, B. and Liu, K. (2021), Electrically Driven Exchange Bias via Solid State Magneto-Ionics, Nano Letters (Accessed October 10, 2025)