Antiferromagnetic half metallicity in codoped chalcopyrite semiconductors Cu(Al1−2xAxBxAl1−2xAxBx)Se2 (A and B are 3d transition-metal atoms)

•Stable dilute magnetic states.•Antiferromagnetic half metallicity.•Curie temperature.•Nullified net magnetic moment and compensated DOS.

Electronic structures and magnetic properties of group I–III–VI2 chalcopyrite-type compounds Cu(Al1−2xAxBxAl1−2xAxBx)Se2 are calculated using the Korringa–Kohn–Rostoker Green's function method, where A (Ti, V, Cr, Mn) and B (Fe, Co, Ni) are 3d transition metal atoms, and x is atomic concentration. We found that codoping of Cr–Co and V–Ni pairs at Al site of host CuAlSe2 exhibit antiferromagnetic (AF) half metallicity with low Curie temperature (TCTC). The AF half metallic property is supported by nullified net magnetic moment and compensated density of states in the minority spin direction. On the other hand, codoping of Cr–Ni, Mn–Co, V–Co, and Ti–Co pairs at Al site of host CuAlSe2 manifest ferrimagnetic half metallicity with a small net magnetization and keeping antiparallel local spin moments. In Mn–Co case TCTC is close to room temperature. Besides, Cr–Fe, V–Fe, and Ti–Ni codoping cases lead to an instable magnetic ordering and therefore obtain a disordered local moment (spin-glass like) state.