Reorientation phase transition and sensitivity of the extraordinary Hall-effect-based sensors

Abstract Spin reorientation phase transition was observed in 5–10 nm thick polycrystalline Ni films at about 150 K. The extraordinary Hall effect resistivity in these films is enhanced by surface scattering and is of the order of 1 μΩ cm. Magnetization reversal in the vicinity of the transition is very sharp due to the development of the multi-domain structure with the out-of-plane anisotropy. As a result, the field sensitivity of the Hall resistance reaches values exceeding 500 Ω/T.