  The great obstacle for practical applications of the quantum anomalous Hall
(QAH) effect is the lack of suitable QAH materials (Chern insulators) with
large non-trivial band gap, room-temperature magnetic order and high carrier
mobility. The Nickle chloride (NiCl3) monolayer characteristics are
investigated herein using first-principles calculations. It is reported that
NiCl3 monolayers constitute a new class of Dirac materials with Dirac
spin-gapless semiconducting and high-temperature ferromagnetism (~400K). Taking
into account the spin-orbit coupling, the NiCl3 monolayer becomes an intrinsic
insulator with a large non-trivial band gap of ~24 meV, corresponding to an
operating temperature as high as ~280K at which the quantum anomalous Hall
effect could be observed. The calculated large non-trivial gap, high Curie
temperature and single-spin Dirac states reported herein for the NiCl3
monolayer lead us to propose that this material give a great promise for
potential realization of a near-room temperature QAH effect and potential
applications in spintronics. Last but not least the calculated Fermi velocities
of Dirac fermion of about 4x105 m/s indicate very high mobility in NiCl3
monolayers.
