Obtaining the anisotropy axes misalignment and dispersion in exchange bias systems by magnetoresistance

Abstract We have studied the dispersion in the anisotropy fields axes and the misalignment between the uniaxial and unidirectional anisotropy axes in exchange bias (EB) systems by angular anisotropic magnetoresistance measurements (AMR). We present here how these two important parameters affect the AMR curves. The EB field dispersion results in different resistance values when measured with the magnetic field applied along or opposed to the average bias field direction. We found that a misalignment between the anisotropy axes produces an asymmetry in the angular AMR curves, similar to the asymmetry caused by the misalignment between the anisotropy axes and the current directions. Careful control on the current direction enable us to identify the origin of the measured asymmetry. In addition, we presented the model and protocol used to perform the calculations and obtain the main parameters related to EB.