Electrically Enhanced Exchange Bias via Solid State Magneto-Ionics
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. Prof. Kai Liu’s group, including graduate student Chris Jensen and postdoctoral fellow Alberto Quintana, along with collaborators at KAUST and NIST, have demonstrated an effective approach to magneto-ionically and electrically tune the exchange bias in Gd/NiCoO thin films, where neither of the layers alone is ferromagnetic at room temperature. The Gd capping layer deposited onto antiferromagnetic NiCoO 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 after a voltage conditioning and subsequently reset with a second field cooling.
These results highlight the viability of the solid-state magneto-ionic approach to achieve electric control of exchange bias, with potential for energy-efficient magneto-ionic devices. The paper is recently published in ACS Applied Materials and Interfaces.