Scaling the anomalous Hall effect: A connection between transport and magnetism

An unconventional form of scaling---one based on the anomalous Hall effect---in Fe0.8Co0.2Si demonstrates the close correlation between its magnetic and transport properties. In particular, this approach enables the universality class of its magnetic phase transition---in fields above 1 kOe---to be reliably established from the anomalous Hall conductivity, yielding TC=36.0±0.5 K, δ=4.78±0.01, β=0.37±0.01, and γ=1.38±0.02. These latter estimates are in excellent agreement with those deduced from conventional magnetic measurements over a comparable field range and lead to the inference that in modest fields the dominant interaction in the critical regime becomes near-neighbor isotropic exchange.