Micromagnetic characterization of a rotation sensor based on the planar Hall effect

Thin films of Ni80Fe20 (Permalloy) and structures as Ni80Fe20/NM/Ni80Fe20 were used to build low cost rotation sensors. The structures were deposited onto oxidized Si wafers. NM denotes Cu or Al2O3 layers. Angular dependencies of the planar Hall effect (PHE) are investigated for different values of the magnetic field strength. A distortion of the angular dependence symmetry with respect to the abscissa axis was observed. This is due to contacts misalignment, hysteretic behaviour of the magnetic material and some coupling effects in the multilayered structure. We performed micromagnetic simulations to discuss the effect of the magnetic field strength on the shape of the angular dependence of PHE. The parameters used for micromagnetic simulations are inspired from the film structure.