Tuning electronic and magnetic properties of V-, Cr-, and Mn-doped PbS via strain engineering: A first-principles proposal

摘要

We theoretically investigated the possibilities of establishing ferromagnetism and tailoring band gap of narrow-gap PbS with early 3d transition-metals (V, Cr, and Mn) doping and strain engineering. The results revealed that these magnetic impurities can be spontaneously incorporated into PbS matrix. Moreover, V- and Mn-doped PbS materials are magnetic insulators, while Cr-doped PbS becomes nearly half metallic. When taking the spin-orbit coupling (SOC) effect into account, the strong p-d hybridization gives rise to the band gap closing for V- and Mn-doped PbS, creating two novel spin-gapless semiconductors. The induced gapless state could be further modulated by external strain, resulting in a topological phase transition with both gap opening and band inversion for V- and Mn-doped PbS systems. Particularly, we find that V-doped PbS is a ferromagnetic compound with intrinsic exchange field, which may be a potential candidate for the realization of quantum anomalous Hall effect.