Co in diamond: Ferromagnetic ordering of a transition metal in diamond

Ferromagnetic ordering of dopants in semiconductors has attracted considerable interest, due to their relevance for “spintronic” applications. Diamond is a wide band gap semiconductor with extreme properties which make it suitable for high power, high frequency and high temperature applications. Up to now mainly other semiconductors have been considered in the search for dilute magnetic semiconductors (DMS). We report ab initio all electron, full-potential density functional theory modeling and show that the transition metal Co will order ferromagnetically when occupying a divacancy in diamond, forming a dilute magnetic semiconductor, with a magnetic moment of 0.4 μ B per supercell, inducing two spin-polarized impurity bands in the diamond band gap. The impurity bands are shown to arise from the hybridization of the Co 3d level with diamond C 2p states. This demonstrates that diamond may be successfully considered in the search for ferromagnetically ordered semiconductors, in particular since diamond based DMS are expected to possess high Curie temperatures, in addition to the other extreme properties of diamond.