Ab initio investigation of the electronic structure and bonding properties of the layered ternary compound Ti3SiC2 at high pressure

摘要

The pressure dependences of the lattice parameters, electronic structure, and bonding properties of the layered ternary compound Ti3SiC2 were investigated by performing ab initio plane-wave pseudopotential total energy calculations. The material exhibited elastic anisotropy. The lattice constants and axial ratio were studied for different pressures, and the same trend was obtained as is measured in experiment. It was found that although the structure was stable at high pressure, the electronic structure and atomic bonding were definitely affected. The electrical conductivity was predicted to reduce with pressure, which was interpreted by analysing the band dispersion curve and density of states at the Fermi level. The strengths of the atomic bonds in Ti3SiC2 were considered by analysing the Mulliken population and by examining the bond length contraction for various pressures. A redistribution of charge density that accompanied high pressures was also revealed. [References: 17]