Magnetic nanostructures by adaptive twinning in strained epitaxial films

TL;DR

This paper presents a novel method to create self-organized magnetic nanostructures in epitaxial films by exploiting the intrinsic instability of Fe70Pd30 alloys, combining experiments and first-principles calculations.

Contribution

It introduces a new lattice relaxation mechanism enabling adaptive nanotwinning in strained epitaxial films, which was not expected for stable materials.

Findings

Achieved 54% coherent epitaxial strain in Fe70Pd30 films

Identified low twin boundary energy as key for adaptive nanotwinning

Demonstrated control over nanostructure and properties in functional materials

Abstract

We exploit the intrinsic structural instability of the Fe70Pd30 magnetic shape memory alloy to obtain functional epitaxial films exhibiting a self-organized nanostructure. We demonstrate that coherent epitaxial straining by 54% is possible. The combination of thin film experiments and large-scale first-principles calculations enables us to establish a lattice relaxation mechanism, which is not expected for stable materials. We identify a low twin boundary energy compared to a high elastic energy as key prerequisite for the adaptive nanotwinning. Our approach is versatile as it allows to control both, nanostructure and intrinsic properties for ferromagnetic, ferroelastic and ferroelectric materials.