Structural, electronic and elastic properties of V 5Si 3 phases from first-principles calculations

Abstract

The phase stability, electronic, elastic and thermodynamic properties of V 5Si 3 has been investigated by using first-principles calculations based on the density functional theory (DFT). In the present calculations, three phases of V 5Si 3 (Cr 5B 3-prototype, W 5Si 3-prototype and Mn 5Si 3-prototype) have been taken into account to check the phase stability. The calculated formation enthalpies indicate that the W 5Si 3-prototype is the stable phase which is in agreement with experiments, whereas the Cr 5B 3-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 Nb 5Si 3. The density of states and bonding charge density of V 5Si 3 within the W 5Si 3-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.