Scaling of the anomalous Hall effect in ferrimagnetic Co90Gd10 thin films

In this work, we have investigated the anomalous Hall effect and longitudinal magnetoresistance in ferrimagnetic Co₉₀Gd₁₀ thin films with thickness from 5 to 40 nm and temperature from 80 to 300 K. In contrast with ferromagnetic materials in which magnetic moments are parallel with each other, Co₉₀Gd₁₀ shows antiparallel configuration between the Co and Gd magnetic moments. This configuration leads the saturation magnetization of Co₉₀Gd₁₀ can be significantly tuned by the variation of the temperature. As the temperature increases from 80 to 300 K, the saturation magnetization of Co₉₀Gd₁₀ increases from 739 to 844 emu /cm³. However, for Co₉₀Gd₁₀ the scaling law σ_xy~ σ_xxⁿ with n = 2.3 holds surprisingly well. Our results indicate that the scaling law usually reported in ferromagnetic materials remains valid for ferrimagnet materials and it is independent of the change of the saturation magnetization, which undoubtedly suggests the universality of the scaling law.