Non-monotonic dependence of the anomalous Hall coefficient scaling parameter in annealed Ga1-x Mn x As epifilms

When plotting the anomalous Hall coefficient (Rs ) and longitudinal resistivty (ρxx ) for a series of annealed Ga1-x Mn x As epilayers (x∼0.055), we find the value of the scaling parameter n, from R S=cρxxn, to range from one, as-grown, to two at an optimal annealing temperature to values greater than three for higher annealing temperatures, similar behavior to certain inhomogeneous systems. This scaling relationship can be a new method to detect secondary phases in ferromagnetic semiconductor systems