Structural, electronic and elastic properties of V5Si3 phases from first-principles calculations

The phase stability, electronic, elastic and thermodynamic properties of V5Si3 has been investigated by using first-principles calculations based on the density functional theory (DFT). In the present calculations, three phases of V5Si3 (Cr5B3-prototype, W5Si3-prototype and Mn5Si3-prototype) have been taken into account to check the phase stability. The calculated formation enthalpies indicate that the W5Si3-prototype is the stable phase which is in agreement with experiments, whereas the Cr5B3-prototype is a potential metastable phase. The elastic constants, bulk modulus, shear modulus and Young’s modulus are calculated in the present work, and are very close to that of the Nb5Si3. The density of states and bonding charge density of V5Si3 within the W5Si3-phase are obtained indicating a strong covalent character of the bonds. Finally, using the Debye-model, the Debye temperature, heat capacity, and thermal expansion have also been calculated and are in good agreement with experimental results.