The influence of pressure on half-metallicity, magnetism and
thermomechanical properties of Fe-based Heusler alloys
Abstract
The half-metallicity of Heusler alloy is quite sensitive to high
pressure and disorder. Therefore, we systematically studied the
half-metallic nature, magnetism and thermomechanical properties of
FeCrTe and FeCrSe Heusler alloys under high pressure using ab initio
calculations based on density functional theory (DFT). The ground state
lattice constants for FeCrTe and FeCrSe alloys are 5.93 and 5.57 Å,
consistent with available theoretical results. The formation energy,
cohesive energy and elastic constant confirmed the thermodynamically and
mechanical stability of both compounds. The FeCrTe and FeCrSe alloys
showed half-metallic character with the band gap of 0.68 and 0.58 eV at
0 Gpa pressure respectively and magnetic moments of 2.01 µB for both
alloys using GGA approximation. The elastic properties have been
scrutinized and found that FeCrTe is ductile and FeCrSe is brittle at 0
Gpa pressure. Under pressure, FeCrSe turn into brittle above 10 Gpa
pressure. Moreover, the average sound velocity Vm, Debye temperature ƟD
and heat capacity CV were predicted under pressure. These outcomes would
advantage in integrating Fe-based half-Heusler alloys in spintronic
devices.