Electronic structure, magnetic, optical and thermodynamic properties of Ni2Mn1-xRexSn and NiMn1-xRexSn Heusler alloys - ab-initio study

The high-throughput material modeling is helpful tools in the search of discovery new Heusler compounds. In this work the electronic, magnetic, optical and thermodynamic properties of new Ni2Mn1-xRexSn and NiMn1-xRexSn Heusler alloys are reported. Ab-initio calculations are based on local density approximation including generalized gradient approximation (GGA and GGA + U). The band structures were computing by means of FPLO, VASP, SPR KKR-CPA and Gibbs2 methods. The calculations have shown the indirect gap (0.8-1.7eV (GGA) and 1.4-2.4 eV (GGA + U)) in Gamma point between 3d (5d) states of Mn (Re). The value of the indirect gap depended of the system. The substitution of Mn by Re leads to the increase of the volume of the unit cell and the modification of the band structure. The total magnetic moment in Ni2Mn1-xRex,Sn and NiMn1-xRexSn decreases with the increasing of Re composition. The tetragonal distortion in Ni2ReSn leads to the minimum of the total energy at c/a =1 and the magnetic moment increases with the increasing of c/a. The electronic and magnetic properties of Ni2MnSn, NiMnSn, Ni2ReSn and NiReSn in the model with vacuum on both sides of the unit cell are different from the bulk materials. In the vacuum model the gap 0.252(0.176) eV is observed in minority spin band in Ni2ReSn (NiReSn), respectively and the spin polarization at the Fermi energy P(E-F) = 1. (C) 2019 Elsevier B.V. All rights reserved.