Room-Temperature Ferromagnetism in [Formula presented] Semiconductors

We report on the discovery of a room-temperature ferromagnetic semiconductor in chalcopyrite [Formula presented] with [Formula presented]. We have also observed that, at temperatures below 47 K, samples for [Formula presented] and 0.2 show a transition to the antiferromagnetic (AFM) state, so that ferromagnetism is well defined to be present between 47 and 312 K. The observation that the AFM phase is most stable at low temperatures is consistent with the predictions of full-potential linearized augmented plane wave total energy calculations and has consequences for other chalcopyrite materials.