Lateral modulation of magnetic anisotropy in tricolor 3d-5d oxide superlattices

TL;DR

This study demonstrates a reversible method to control magnetic anisotropy and easy-axis orientation in 3d-5d oxide superlattices through interfacial oxygen octahedral coupling, enhancing their potential for spintronic applications.

Contribution

It introduces a new approach to reversibly switch magnetic easy-axis in oxide superlattices by manipulating interfacial oxygen octahedral coupling effects.

Findings

Magnetic anisotropy energy is increased over tenfold in superlattices.

Reversible reorientation of magnetic easy-axis between (100) and (110) directions.

First-principles calculations reveal strong spin-orbit coupling effects in SrIrO3.

Abstract

Manipulating magnetic anisotropy (MA) purposefully in transition metal oxides (TMOs) enables the development of oxide-based spintronic devices with practical applications. Here, we report a pathway to reversibly switch the lateral magnetic easy-axis via interfacial oxygen octahedral coupling (OOC) effects in 3d-5d tricolor superlattices, i.e. [SrIrO3,mRTiO3,SrIrO3,2La0.67Sr0.33MnO3]10 (RTiO3: SrTiO3 and CaTiO3). In the heterostructures, the anisotropy energy (MAE) is enhanced over one magnitude to ~106 erg/cm3 compared to La0.67Sr0.33MnO3 films. Moreover, the magnetic easy-axis is reversibly reoriented between (100)- and (110)-directions by changing the RTiO3. Using first-principles density functional theory calculations, we find that the SrIrO3 owns a large single-ion anisotropy due to its strong spin-orbit interaction. This anisotropy can be reversibly controlled by the OOC, then reorient the easy-axis of the superlattices. Additionally, it enlarges the MAE of the films via the cooperation with a robust orbital hybridization between the Ir and Mn atoms. Our results indicate that the tricolor superlattices consisting of 3d and 5d oxides provide a powerful platform to study the MA and develop oxide-based spintronic devices.