Strain enhanced magnetic anisotropy in SmCo/BaTiO₃ multiferroic heterostructures

We report on the changes in magnetic properties of SmCo/BaTiO₃ multiferroic heterostructures as the BaTiO₃ substrate undergoes its structural phase transitions. The observations show that the macroscopic magnetization of the SmCo film is affected by the structural phase transitions of the BaTiO₃ substrate. Kerr microscopy images show that the magnetic domains of SmCo films have a zigzag shape but their shape is not influenced by the strain transferred from the substrate during the structural phase transitions. Analysis of the magnetoelastic energy shows that the macroscopic change of the magnetization is accompanied by an enhancement of the magnetic anisotropy for the orthorhombic phase of the BaTiO₃ substrate and not a change in symmetry of the anisotropy.