The magnetism of Fe4N/oxides (MgO, BaTiO3, BiFeO3) interfaces from first-principles calculations

Abstract

The geometry, bonding, electronic and magnetic properties of Fe₄N/oxides (MgO, BaTiO₃ and BiFeO₃) interfaces with different configurations are performed using first-principles calculations. The n- and p-type doping of MgO are induced in Fe^IFe^II/MgO and (Fe^II)₂N/MgO interfaces, respectively. The metallic characteristics are induced in BaTiO₃ by contact with Fe^IFe^II termination, followed by p-type doping in the (Fe^II)₂N/BaO interface and n-type doping in the (Fe^II)₂N/TiO₂ interface. The interfacial dipole due to charge rearrangement may induce the Fermi level pinning in the Fe₄N/MgO and (Fe^II)₂N/BaTiO₃ systems. The deposition of Fe₄N on BiFeO₃ leads to a metallic character of BiFeO₃ with total magnetic moments of 0.33–1.54 μ_B. The different electronic and magnetic characters are governed by interfacial bonding between Fe₄N and oxides. These findings are useful for the future design of Fe₄N/oxides based spintronics devices.