Atomistic Simulation on the Structure and Lattice Vibrations of Fe7-xCrxC3 Carbides

摘要

The phase stability and site preference of transition metal carbides Cr in Fe7-xCrxC3 are studied based on the pair potentials obtained by the lattice inversion method.The lattice constants and cohesive energy of Fe7-xCrxC3 with the content x are calculated.The results show that Cr atoms substitute for Fe with a strong preference for the 6c1 sites and the order of site preference is 6c1,6c2 and 2b.Calculated lattice parameters are in good agreement with the experimental data.Moreover,the total and partial phonon densities of states are first evaluated for the Fe7-xCrxC3 compounds with the hexagonal structure.We also provide some information on the vibrational properties of transition metal carbides,such as the specific heat and Debye temperature were also evaluated.