Termination control of magnetic coupling at a complex oxide interface

TL;DR

This study demonstrates how controlling the atomic termination of complex oxide interfaces can precisely tune magnetic coupling, enabling the design of interfaces with tailored magnetic properties for advanced electronic applications.

Contribution

We developed a method to fabricate and characterize ABO3 oxide interfaces with controlled termination, revealing how termination influences magnetic coupling behavior.

Findings

Strong antiferromagnetic coupling at MnO2-SrO interface

Coupled reversal of Mn and Ru magnetic moments

Termination-dependent magnetic interactions

Abstract

Atomically flat interfaces between ternary oxides have chemically different variants, depending on the terminating lattice planes of both oxides. Electronic properties change with the interface termination which affects, for instance, charge accumulation and magnetic interactions at the interface. Well-defined terminations have yet rarely been achieved for oxides of ABO3 type (with metals A, B). Here, we report on a strategy of thin film growth and interface characterization applied to fabricate the La0.7Sr0.3MnO3-SrRuO3 interface with controlled termination. Ultra-strong antiferromagnetic coupling between the ferromagnets occurs at the MnO2-SrO interface, but not for the other termination, in agreement with density functional calculations. X-ray magnetic circular dichroism measurements reveal coupled reversal of Mn and Ru magnetic moments at the MnO2-SrO interface. Our results demonstrate termination control of magnetic coupling across a complex oxide interface and provide a pathway for theoretical and experimental explorations of novel electronic interface states with engineered magnetic properties.