Evidence of metallic clustering in annealed Ga1-xMnxAs from atypical   scaling behavior of the anomalous Hall coefficient
  We report on the anomalous Hall coefficient and longitudinal resistivity scaling relationships on a series of annealed Ga1-xMnxAs epilayers (x~0.055). As-grown samples exhibit scaling parameter n of ~ 1. Near the optimal annealing temperature, we find n ~ 2 to be consistent with recent theories on the intrinsic origins of anomalous Hall Effect in Ga1-xMnxAs. For annealing temperatures far above the optimum, we note n > 3, similar behavior to certain inhomogeneous systems. This observation of atypical behavior agrees well with characteristic features attributable to spherical resonance from metallic inclusions from optical spectroscopy measurements. 
H.K. Choi, W.O. Lee, Y.S. OH, K.H. Kim, Y.D. Park, S.S.A. Seo, T.W.   Noh, Y.S. Kim, Z.G. Khim, I.T. Jeong, J.C. Woo and S.H...