Functionalities enhancement by an anisotropic strain competition

It is generally believed that epitaxial thin films are subject to compressive strain by the nearest layer with a smaller lattice constant or to tensile strain by the nearest layer with a larger lattice constant. Our experimental and theoretical results show that the above viewpoint is not always effective if the interface is anisotropic in the plane. We propose a novel strain mechanism that takes into account the pre-strain state as a key factor rather than considering only the lattice mismatch. Therefore, this anomalous strain model is potentially important for various multifunctional devices based on strain coupling.

Automated summary

Epitaxial thin films may not always experience compressive or tensile strain from the nearest layer with a smaller or larger lattice constant, respectively, if the interface is anisotropic in the plane. A novel strain mechanism, taking the pre-strain state into account as a key factor rather than just considering lattice mismatch, is proposed. This anomalous strain model could be significant for various multifunctional devices based on strain coupling.