Ferromagnetic Half Metallicity in Doped Chalcopyrite Semiconductors Cu(Al1−xAx)Se2 (A = 3d Transition-Metal Atoms)

Abstract

We calculate electronic states and magnetic properties of 3d transition metal (TM) atom doped chalcopyrite-type materials Cu(Al1−xAx)Se2, where A = Ti, V, Cr, Mn, Fe, Co, and Ni, using the Korringa–Kohn–Rostoker Green’s function method. Some of the chalcopyrite compounds Cu(Al1−xAx)Se2 exhibit a stable ferromagnetic half metallic (FHM) state relative to a disordered local moment (DLM) state, which simulates a paramagnetic state. FHM states evince Curie temperatures (TC) above room temperature when low-concentration (10%) TM impurity ions Cr and Mn are doped at the host Al site, whereas Ti and V doping manifests half metallicity with TC nearly equal to and lower than room temperature, respectively. On the contrary, in Fe, Co, and Ni doped compounds instability of ferromagnetic states to DLM is obtained. The heats of formation by Mn doping in CuAlSe2 at the Al and Cu sites are estimated and the site preference at Al is realized.