Enhancement of the anomalous Hall effect via interfacial scattering in thick Fe nanocluster-assembled thin films

Abstract

Fe nanocluster-assembled thin films with thicknesses ranging from 1000 to 1400 nm were fabricated using the plasma-gas-condensation technique. The study reveals that the films composed of Fe nanoclusters have an average grain size of approximately 7.7 nm, and throughout the temperature span of 5 to 300 K, the films exhibit an anomalous Hall coefficient (R_s) reaching approximately 1.0–2.5 × 10⁻⁸ Ω cm G⁻¹, which is nearly 4 orders of magnitude greater than that of bulk Fe, showing a significant giant Hall effect (GHE). Additionally, the longitudinal resistivity (ρ_xx) decreases gradually with increasing film thickness, while the saturated anomalous Hall resistivity (ρ^A_xy) demonstrates a corresponding gradual increase. In particular, in a double logarithmic coordinate system, log ρ^A_xy increases as log ρ_xx decreases, exhibiting adherence to a new scaling relation expressed as log(ρ^A_xy/ρ_xx) = a + b log ρ_xx.