Low-field linear magnetoresistance and transport parameters of (Cd _1-x Mn _x ) _3 As _2 polycrystals

In this study, we analyzed the composition-dependent phenomena in (Cd _1-x Mn _x ) _3 As _2 polycrystals with x = 0 – 0.08. We showed that the Mn-induced stabilization of minor α” -phase in these systems occurs without substantial decrease in the characteristic crystallite sizes. The comparison of the estimated relevant length scales suggests that polycrystalline character of the studied samples plays only a minor role in electron transport, while the increase in defect density along with Mn content has more profound effect. We observed low-temperature linear magnetoresistance even for the samples with high Mn content. The decrease in the corresponding effect amplitude can be explained in terms of basic properties of the parent Cd _3 As _2 compound. Therefore, we argue that Mn-doping qualitatively conserves characteristic features of the Dirac semimetal phase in the system with relatively high Fermi energies, in accordance with previous band calculations of the (Cd _1-x Mn _x ) _3 As _2 compound.