The synergistic character of the defect-induced magnetism in diluted magnetic semiconductors and related magnetic materials.

In this work, we introduce a new perspective in explaining the origin of magnetism in dilute magnetic semiconductors, carbon-based materials and other related materials. According to our proposal, the magnetism in these materials is the result of the synergistic action of defect-induced electronic processes mostly of local character which can provide magnetic moments and develop a ferromagnetic coupling among them. This synergy is realizable via appropriate codoping which appears as a general and generic approach. In the present report, we use ab initio results to demonstrate that in a diverse sample of systems including codoped ZnO, GaN, TiO(2) and carbon-based materials, the ferromagnetic coupling that is developed among the doped (or defect-induced) magnetic moments results from the interaction of spin-polarized neighborhoods centered at the defect sites. Our results also give evidence that bipartite codopant configurations can further enhance the ferromagnetic features of these systems significantly.