First principles study of the magnetism of diluted magnetic semiconductors

Modern spin-electronics defines high requirements for the design and fabrication of new materials. Dilute magnetic semiconductors take an important position among the materials that can fulfill these requirements. Here we report on the results of some of our first-principles studies on these materials. We show that partially filled electronic bands play an important role in the magnetism of these systems. The long-range exchange interaction appears as a compromise between the delocalization of the hole states from the 3d impurities and the strength of the 3d-hole interaction. The properties of this compromise depend strongly on the system studied and can be determined only within the framework of the realistic first-principles density-functional-theory calculations