Characterization of anti-phase boundaries in epitaxial magnetite films

The occurrence of anti-phase domain boundaries (APBs) in epitaxial Fe3O4 films has a strong influence on the resistivity, magnetic and magneto-resistance properties of these films. It is therefore important to understand the configuration and magnetic coupling across the boundary. We have studied the distribution of shift vectors and the relationship between the shift vector and the boundary plane and the resulting magnetic coupling at the boundary. The vast majority of APBs have $1/4\langle110\rangle$ shifts while those with 1/2[100] shift are very uncommon. Approximately 45% of APBs have shift vectors in the plane of the film. Their boundary plane is perpendicular to the shift vectors and in this case the magnetic coupling can be either ferromagnetic or anti-ferromagnetic. The remaining 55% of APBs have shift vectors out of the film plane, with the boundary planes not perpendicular to the shift vector but close to {100} or {310}, resulting in a ferromagnetic coupling when the boundary plane is {100} and in an anti-ferromagnetic coupling when the boundary plane is {310}