First-Principles Study of the Interfaces between Fe and Transition Metal Carbides

Abstract

The interface energies and electronic structures of the interfaces between BCC Fe and transition metal carbides have been investigated using first-principles calculations based on density functional theory. The effects of the composition and configuration of the carbides on the interface properties have been determined. It was shown that the Fe/TiC interface has the highest interface energy and the formation of complex carbides leads to a significant decrease in the interface energy. The complex carbide of (Ti 0.5 Mo 0.5 )C, which has Mo present at the interface, has been found to be the most stable. From the analysis of the density of states, the stability of the Mo-segregated (Ti 0.5 Mo 0.5 )C carbides has been revealed to be due to the hybridization of the d-orbitals in the t 2g local symmetry between Mo and its first nearest neighboring Fe atoms.