Role of electronic binding energy on the stability of B, C, N, and O in Fe

Using first-principles density functional theory (DFT), we separate the distortion energy (DE) on Fe due to the introduction of solute atoms like B, C, N, and O at different sites from the electronic binding energy (EBE) of a solute atom with Fe. Contrary to the belief that distortion energy alone dictates the preference of solute atoms for a site in bulk, we show that EBE dictates the preference of the O for the octahedral site in Fe, with DE being the highest at the site. The site preference for C and N in bulk Fe is dictated by both DE and EBE. However, DE alone dictates site preference for B. The DE of solute atoms cannot be predicted by calculated radius, which is highest for B and lowest for O. We find that O and B have similar distortion energy due to large charge transfer to the O atom from Fe.

Automated summary

This study examines the preference of solute atoms for different sites in Fe using first-principles density functional theory. The results show that the preference of O for the octahedral site is determined by the electronic binding energy (EBE), while the distortion energy (DE) is highest at that site. The preference of C and N in bulk Fe is influenced by both DE and EBE. However, DE alone dictates the site preference for B. The DE of solute atoms cannot be predicted by their calculated radius, as B, despite having the largest radius, has similar distortion energy to O due to a large charge transfer.