Strain engineering magnetic frustration in perovskite oxide thin films

TL;DR

This paper demonstrates how epitaxial strain can induce and control magnetic frustration in multiferroic BiFeO3 thin films, revealing a tunable magnetic state that can be manipulated via substrate choice.

Contribution

It introduces a method to engineer magnetic frustration in multiferroic thin films through strain, showing the possibility of controlling magnetic order via substrate selection.

Findings

Magnetic frustration can be induced in BiFeO3 thin films.

Epitaxial strain can tune the magnetic order, even annihilating 3D spin order.

The effects are predicted to occur in BiCoO3 as well.

Abstract

Our first-principles results show that geometric frustration can be induced in thin films of multiferroic BiFeO3. We find that competing magnetic interactions occur in the so-called super-tetragonal phase of this material, which can be grown on strongly-compressive substrates. We show that the frustration level can be tuned by appropriately choosing the substrate; in fact, the three-dimensional spin order gets totally annihilated in a narrow range of epitaxial strains. We argue that the effects revealed here are not exclusive to BiFeO3, and predict that they also occur in multiferroic BiCoO3.