Structural Electronic and Magnetic Characterisation of Mn2FeSn Heusler Alloy

Abstract

In this master thesis, we present the first-principle calculations of the structural, electronic and magnetic properties of the inverse Heusler compound Mn2FeSn with discussions in order to identify the characteristics in the interest of spintronics devices. To determine its properties, we carried out a theoretical study using the pseudo-potential approximation coupled to the plane wave (PP-PW) within the framework of the density functional theory (DFT) implemented in CASTEP. The exchange-correlation potential was treated by generalized gradient approximation (GGA) according to Perdew, Burke and Ernzerhof (PBEsol). We performed a geometric optimization under stress between -12 and 12 GPa for the three predicted structures of the compound in order to obtain the most stable. At equilibrium state, we have discovered that the compound Mn2FeSn behaves like a halfmetal semiconductor, metal and a gapless half-metal, according to the different values of the pressure imposed. The total and partial density of state indicates a polarization ratio equal to (57%) calculated at the Fermi level. The found value of the magnetic moment of 2 μB agrees with the Slatter-Pauling rule. The subject compound of our study exhibits a great diversity of behaviour under hydrostatic pressure. Which makes him a promoter candidate for the next generation of spintronic applications and nanoelectronic devices.