Comment on 'Fourfold symmetric anisotropic magnetoresistance based on magnetocrystalline anisotropy and antiphase boundaries in reactive sputtered epitaxial Fe_3O_4 films' [Appl. Phys. Lett. 96, 092502 (2010)]

摘要

The authors report in their letter on measurements of the angular dependent anisotropic magnetoresistance (AMR) of magnetite films grown on (001), (110), (111), and (112) MgO substrates. Contrary to the expectations of the "traditional theory" p=p_⊥ + (p_‖-p_⊥)cos~2 θ the authors found an AMR contribution with fourfold symmetry. This was explained to originate from the magnetocrystalline energy as well as antiphase boundaries. In the formula above p_‖ and p_⊥ denote the resistivities for the magnetization parallel or perpendicular to the current density. θ denotes the angle between current density and magnetization.