Field-direction sensitive magnetization reversal in a perpendicularly exchange-coupled system

Field-direction dependence of Hall resistance and anisotropic magnetoresistivity has been systematically investigated in a perpendicularly exchange-coupled [Pt/Co]/IrMn system. We combine the results of anomalous Hall effect and planar Hall effect to describe the process of magnetization reversal at all field angles. These measurements provide strong evidence that the Hall resistance is closely related to different field directions in the normal plane as well as in the film plane, revealing the sensitivity of the signals to the field direction even when it is slightly deviated from the film plane. These observed correlations between electrical properties and magnetization in the perpendicular exchange coupling system would not only help to understand the spin alignments of an exchange-coupled magnet, but also propose a possible magnetic sensor for full space detection, opening a promising avenue to detect a wide range of magnetic fields at all angles. (paper)