Electronic, magnetic and magnetotransport properties of Mn-doped Dirac semimetal Cd3As2

Doping by Mn breaks the time-reversal and crystal symmetry of Cd3As2, splits Dirac cones and changes band structure. We study these changes using both DFT calculations and magnetotransport measurements. Our band structure of Cd3As2 is confirmed by calculations of dielectric tensor and reflectivity consistent with an experiment. Calculations take into account the n-carrier density of Cd3As2 samples similar to 1.10(18) cm(-3) which shifts the Fermi level by epsilon(F) similar to 50 meV. The Mn-doping of Cd3As2 is simulated with the Cd46Mn2As32 cell for 9 configurations of Mn atoms. Our simulation shows the preference for antiferromagnetic spin order and tendency towards Mn clustering. Doping by Mn causes transition of Cd3As2 into a trivial topological state with a gap of E-g approximate to 40 meV. Our experimental studies of (Cd1-xMnx)(3)As-2 show that a negative sign of magneto-conductivity is observed at x = 0 and 0.017, but changes to a positive one at x = 0.033 . We argue, this sign change is closely connected with the gap opening and is basically controlled by the ratio E-g/epsilon(F). (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Doping of Mn disrupts the crystal symmetry of Cd3As2 and transitions it into a trivial topological state with a gap of around 40 meV. Experimental studies show that the change in magneto-conductivity is closely related to the opening of the gap under different doping ratios.