Manganese-doped CdGeAs2, ZnGeAs2 and ZnSiAs2 chalcopyrites: A new materials for spintronics

Based on Mn-doped chalcopyrites CdGeAs2, ZnGeAs2 and ZnSiAs2 the new dilute magnetic semiconductors with p-type conductivity were produced. Magnetization, electrical resistivity, magnetoresistance and Hall effect of mentioned compositions were studied. Their curves of temperature dependence of magnetization have the similar form in spite of complicated character, for which the concentration and mobility of the charge carriers are responsible. Thus, for T < 15 K, these curves are characteristic for superparamagnetics and for T > 15 K for a frustrated ferromagnetics. In compounds with Zn these two states dilute by spinglass-like state. This specific feature is assigned to an attraction of Mn ions occupying neighboring sites and to the competition between the carrier-mediated exchange and superexchange interactions. Curie temperatures of these compounds are above room temperature. These are the highest Curie temperatures in the A(II)B(IV)C(2)(V):Mn systems. (C) 2011 Elsevier B.V. All rights reserved.