First principles calculations of the stability of the T2 and D8(8) phases in the V-Si-B system

The crystal and electronic structures of D8(1)-V5SiB2 and D8(8)-V5Si3B ternary compounds have been investigated by means of first principle calculations. The calculated structural parameters are in very good agreement with the experimental data. The calculated values of the enthalpies of formation at T = 0 K of the D8(1)-V5SiB2 and D8(8)-V5Si3B ternary compounds are -67.1 and -62.1 kJ/mol of atoms respectively. The total and partial electronic densities of states show a strong hybridization between the B p states and V d states. The defect enthalpies of formation as well as the mixing enthalpies have been computed. These data are essential for the modeling of the D8(1) and D8(8) phases in the V Si B ternary system. A partial V-VSi2-VB isothermal section at 298 K is proposed. (C) 2014 Elsevier Ltd. All rights reserved.