Anisotropic galvanomagnetic effects in single-crystal Fe(001) films elucidated by a phenomenological theory

Utilizing the phenomenological theory based on crystal symmetry operation, we have established the complete angular dependencies of the galvanomagnetic effects, encompassing both anisotropic magnetoresistance (AMR) and the planar Hall effect (PHE), for the ferromagnetic films with ${C}_{4v}$ symmetry. These dependencies were experimentally confirmed via comprehensive angular mapping of AMR and PHE in single-crystal Fe(001) films at room temperature. We demonstrated that the intrinsic magnetization-induced effects are independent of the field strength by carefully separating the field-induced and magnetization-induced galvanomagnetic effects. Our theoretical and experimental findings highlight the absence of in-plane fourfold angular dependence in PHE, a feature prohibited by the Onsager relation in systems with ${C}_{4}$ symmetry. This study affirms that the universal angular dependencies of AMR and PHE in single crystals can be accurately predicted by the conventional phenomenological theory.