Magneto-Ionic Control of Heterostructures and Interfaces

Kai Liu, Georgetown University 

October 27, 2020

Magneto-ionic approaches for modifying ion distributions in metal/ionic-reservoir heterostructures offer exciting potentials to control materials properties. Our recent studies show that such magneto-ionic effect, even though initiated at metal/reservoir interface, can extend deep into the rest of the reservoir layer [1-5]. In this talk I will illustrate a number of functionalities that can be tuned via the magneto-ionic handle: In antiferromagnetic NiCoO systems, we have observed a strong exchange bias due to the magneto-ionic effect, which can be further enhanced by electric biasing. In studies of cuprates, a thin Gd layer (up to 20 nm) deposited on top of epitaxial YBCO films (100nm) is found to leach oxygen from deep within the YBCO and suppress the superconductivity [4]. In ferromagnets chemisorbed with submonolayer oxygen, we have observed strong DMI induced by chemisorption at room temperature, which allows manipulations of magnetic skyrmions [5]. Time permitting, results on nitride and hydroxide systems will also be presented. Our findings demonstrate an effective ionic approach to control interfaces in magnetic heterostructures.

Supported by the NSF (DMR-1610060, ECCS-1611424, DMR-1905468, ECCS-1933527) and the nCORE SMART center through SRC/NIST.

[1]. Gilbert, et al, Nat. Commun., 7, 11050 (2016).
[2]. Gilbert, et al, Nat. Commun., 7, 12264 (2016).
[3]. Gilbert, et al, PR Mater. 2, 104402 (2018).
[4]. Murray, et al, ACS Appl. Mater. Interfaces 12, 4741 (2020).
[5]. G. Chen et al, Sci. Adv. 6, eaba4924 (2020).