About anomalous g-factor value of Mn related defects in GaAs:Mn
  The results of experimental investigations of ESR spectra of manganese impurity ions in a GaAs : Mn system are presented. The studies are done for various a Fermi level position relative to valence band edge in the system. Characteristic defects for the system that give rise to lines with g factors of 5.62 and 2.81 in the ESR spectra are studied in some detail. The experimental results are discussed in the framework of a previously developed model with a double defect involving the impurity ion. The "3d5 + hole" model is a special case of the double defect model in this system. An analytical expression for the covalent renormalization of the g factor of an ESR line in this system is obtained. 
S. M. Yakubenya, K. F. Shtelmakh
cond-mat.mtrl-sci