Computational investigation of elastic properties of hypothetical Half-Heusler compounds XNbSn under hydrostatic pressures

We investigated the electronic, elastic, and magnetic properties of the hypothetical half- Heusler alloys with Niobium base atom, XNbSn with (X= Cr, Mn, Co, Fe, V) uses the full-potential (linearized) augmented plane-wave and local-orbitals FP-(L)APW + lo basis set in the WIEN2K ab-initio package based on density functional theory (DFT). We investigated the elastic constants, Shear modulus, young modulus, and bulk modulus of these alloys under different pressures (0, 20, 40, and 80 GPa). We predicted that CoNbSn behaves as a semiconductor with a direct energy gap of 0.99 eV, while the other half- Heusler alloys show a metallic behavior. CoNbSn keeps its semiconductor behavior under higher pressures up to 80 GPa. Both of VNbSn and CrNbSn have a high value of magnetic moments of 2.158 and 3.002 µB respectively. All XNbSn alloys are stable mechanically at different pressures according to the Born-Huang conditions. CoNbSn, FeNbSn, CrNbSn, and MnNbSn behave as a ductile material at ambient pressure.