Anomalous in-plane magnetic anisotropy in strain-mediated converse magnetoelectric coupling.

Magnetic axis rotation (MAR) in ferromagnetic (FM) layers is crucial for strain-mediated converse magnetoelectric coupling. Employing the density functional theory (DFT), we computationally study the magnetic anisotropy of selected deformed FM materials such as body-centered iron. The results show that the short axis is more energy-favorable at high in-plane strain difference than previously predicted phenomenologically. This anomalous trend and the complex energy behaviors at different strain conditions explain why spin-lattice dynamics (SLD) simulation does not produce in-plane MAR and imply couplings between different energy terms together with high order coefficient contributions.