A first-principles study on the magnetoelectric coupling induced by Fe in two-dimensional BaTiO3 (001) ultrathin film
First-principles approach is utilized to study the magnetoelectric coupling induced by Fe in two-dimensional BaTiO3 (001) ultrathin film. It is observed that the impurity Fe increases the total magnetic moment, but suppresses the spontaneous polarization. Furthermore, the total magnetic moment of Fe replacing Ti is influenced by the distance between dopants, which decreases with reducing the distance. Study on spin-orbit coupling under bi-axial compressive strain shows a strong magnetoelectric coupling in case of Ti-substitution, and for the configuration with neighbouring Fe, it is more readily to be adjusted relative to that with Fe distant to each other. While, the replacement of Ba exhibits a negligible interaction between spontaneous polarization and magnetic moment. Clearly, our current work may indicate that the careful substitution of Ti by Fe atoms can realize two-dimensional BaTiO3 behaving in the manner of multiferroics.