First-principles investigations on the structural stability, thermophysical and half-metallic properties of the half-Heusler CrMnS alloy

Y Half-Heusler alloys are anticipated to impact real applications for instance industrial waste heat recovery due to their high thermoelectric (TE) properties, good thermal stability, and excellent elastic properties. The state-of-the-art density functional theory (DFT) is used to calculate the electronic structure, magnetic, elastic, thermodynamic, and transport properties of the cubic CrMnS half-Heusler (HH) alloy. Ferromagnetic (FM) configuration is found to be energetically most favorable than non-magnetic (NM) and antiferromagnetic (AFM) states for the HH CrMnS alloy. The spin-resolved band structure of HH CrMnS prevails its half-metallicity at the Fermi level with a total magnetic moment of 1 mu(B). The cohesive and formation energy analysis along with the phonon dispersion curve indicate that HH CrMnS is a chemically, thermodynamically, and vibrationally stable compound. Elastic properties for the studied compound show its mechanical stability, anisotropic & brittle nature with high hardness, and Debye temperature of 410 K. Thermodynamic parameters are also calculated which depict the stability of the studied alloy at varied pressure and temperature. Furthermore, thermoelectric (TE) properties indicate that HH CrMnS alloy has a maximum value of power factor (PF) equal to 3.3 x 10(11) WK-2 m(-1) s(-1) at 1000 K and ZT value of 0.72 at 600 K. The vibrational and mechanical stability, higher bandgap (similar to 0.96 eV) and 100% spin-polarization demonstrate that HH CrMnS can be a potential alloy for TE and spintronic applications.

Automated summary

Y Half-Heusler alloys, such as the cubic CrMnS half-Heusler (HH) alloy, are expected to have high thermoelectric properties and stability, making them promising for applications in industrial waste heat recovery. This study utilized density functional theory (DFT) to analyze the electronic structure, magnetic properties, elastic properties, thermodynamics, and transport properties of HH CrMnS. The results showed that the alloy has favorable ferromagnetic configuration and half-metallicity, as well as stability in terms of chemistry, thermodynamics, and vibrations. Additionally, the alloy exhibited high mechanical stability, anisotropic and brittle nature, and promising thermoelectric properties. The findings suggest that HH CrMnS could be a potential alloy for thermoelectric and spintronic applications.