Magnetic exchange mechanism in 3d transition-metal-doped LiZnAs

Abstract

First-principles calculations were performed to study the electronic structure and magnetic properties of Li(ZnTM)As (TM = Ti, V, Cr, Mn, Fe, Co, Ni). The results showed that V, Cr, Mn and Fe were the most promising magnetic dopants for LiZnAs based DMSs. The magnetism of the doping systems originated from p-d hybridization. Among all the TM atoms, the maximum atomic magnetic moment provided by Mn was 4.74 μB. The ferromagnetic ground states were achievable in Ti-, V- or Cr-doped LiZnAs, and Li(ZnCr)As had the strongest ferromagnetic stability. Whereas, Mn-, Fe-, Co- or Ni-doped LiZnAs was antiferromagntic stable. To stabilize the ferromagnetism efficiently by the double exchange mechanism, there had to be delocalized anti-bonding states occupied partially. The antiferromagnetic super-exchange dominated when the 3d shells of magnetic impurities were half-filled or more than half-filled.