Enhanced anomalous Hall effect in Fe nanocluster assembled thin films.

An enhanced anomalous Hall effect is observed in heterogeneous uniform Fe cluster assembled films with different film thicknesses (ta = 160-1200 nm) fabricated by a plasma-gas-condensation method. The anomalous Hall coefficient (Rs) at ta = 1200 nm reaches its maximum of 2.4 × 10(-8) Ω cm G(-1) at 300 K, which is almost four orders of magnitude larger than bulk Fe. The saturated Hall resistivity (ρ(A)xy) first increases and then decreases with the increase of temperature accompanied by a sign change from positive to negative. Analysis of the results revealed that ρ(A)xy decreases with increasing longitudinal resistivity (ρxx) on a double-logarithmic scale and obeys a new scaling relation of log(ρ(A)xy/ρxx) = a0 + b0 log ρxx.