Non-monotonic dependence of the anomalous Hall coefficient scaling parameter in annealed Ga1−xMnxAs epifilms

Abstract When plotting the anomalous Hall coefficient ( R s ) and longitudinal resistivty ( ρ xx ) for a series of annealed Ga 1− x Mn x As epilayers ( x ≈0.055), we find the value of the scaling parameter n , from R S = cρ xx n , 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.