First-principles calculations on the electronic structure and cohesive properties of titanium stannides

摘要

First-principles calculations based on the density-functional theory were employed to investigate the electronic structure and cohesive properties of Ti-Sn alloys. Based on the calculated results, the lattice constants, bulk modulus and formation energies for the Ti-Sn intermetallics were compared with previous experimental and theoretical investigations. It was demonstrated that in term of the means volume and cohesive properties, the structure stability of Ti-Sn intermetallics increased with decreasing Ti composition, which was also supported by the analysis of densities of states. Furthermore, it was found that the difference in stability between the Ti-Sn intermetallics could be attributed to the bonding electron numbers at the upper region of the valence-band complex, which was cut by Fermi level. In addition, the electronic structure of the Ti-Sn intermetallics also showed a strong hybridization between Ti 3d and Sn 5p states, which played a dominant role in the bonding mechanism of Ti_3Sn and Ti_2Sn.