Switching of the symmetry of magnetic anisotropy in Fe/BaTiO3 heterostructures

Switching of the symmetry of magnetic anisotropy is clearly demonstrated in an epitaxial Fe layer on BaTiO3, in association with the interface lattice distortion occurred at the structural phase transition of BaTiO3. The polar plot of the normalized remanent magnetization shows the fourfold symmetry with the magnetization easy axis along [100] of Fe at room temperature, while that at 230 K exhibits the twofold symmetry with the easy axis along [110]. Spatially resolved micro-Raman inspection corroborates the fact that the change in the magnetic symmetry arises from the magnetoelastic coupling at the interface.