Incorporation of transition metal elements into the tetradymite structure of Sb2Te3 had a strong influence on electronic properties. Recent studies had indicated that Mn substitutes on the Sb sub-lattice increased the carrier concentration of holes. However, the doping efficiency of Mn appeared rather low in comparison to what it should have been, based upon the measurements of magnetization, structural analysis and transport properties. The issue was tackled here by making detailed studies of the Hall effect and electrical resistivity and the results were explained with the aid of a model that took account of interactions of the Mn impurity with the native defects in antimony telluride. It was found that Mn atoms interacted with antisite defects (Sb atoms located on the Te sub-lattice); a process that decreased the density of antisite centers and generated free electrons. These, in turn, recombined with holes and thus decreased their concentration and the apparent Mn doping efficiency.

Defect Structure of Sb2−xMnxTe3 Single Crystals. J.Horák, P.Lošták, Č.Drašar, J.S.Dyck, Z.Zhou, C.Uher: Journal of Solid State Chemistry, 2005, 178[9], 2907-12