Ab-initio prediction of high TC half-metallic ferrimagnetism in Li-based Heusler compounds Mn2LiZ (Z = Si, Ge and Sn)

Abstract Using density functional theory, we have investigated the structural, electronic, magnetic and thermoelectric properties of the new full-Heusler compounds Mn2LiZ (Z = Si, Ge and Sn). We showed that the three studied compounds favour the inverse Heusler structure with a ferrimagnetic ground-state. In the basis of the formation energy calculation the compounds are thermodynamically stable. The magneto-electronic investigation shows for all compounds a half-metallic ferrimagnetism with a fairly large gap and a low net spin magnetic moment of only 1 μB, obeying to the Slater-Pauling rule. Strong inter-sublattice exchange interactions are found and a mean field approximation reveals a high Curie temperature TC which exceeds 1000 K. Thermoelectric and electronic transports were determined within Boltzmann's transport theory and their analysis results are discussed in detail.