First-principles calculations on adsorption-diffusion behavior of transition layer Ti atoms on the Fe surface

Abstract

When preparing films through magnetron sputtering, atoms of the target material ejected during sputtering adhere, diffuse across the surface, condense, nucleate, and grow on the substrate surface, ultimately forming a film. However, due to the short time scales involved in this process, it is difficult to acquire detailed knowledge about the adsorption, surface diffusion, and film formation of target material atoms on the substrate surface in experimental settings. Therefore, this paper employs first-principles calculation methods to investigate the strongest adsorption sites, optimal diffusion paths, and the impact of diffusion distance of Ti atoms on the Fe(110) and Fe(100) surfaces on the film’s microstructure. Through theoretical calculations, this study enriches the theoretical understanding of this process, providing a theoretical basis for the design and analysis of experimental schemes. The calculation results indicate that the adsorption energy of Ti atoms is the highest at the B sites on the Fe(100) surface. The diffusion barrier for Ti atoms on the Fe(100) surface is the lowest, making it easier for Ti atoms to diffuse on this surface. Under the condition of a relative substrate temperature labeled as Ts/Tm<0.3, the average diffusion distance of Ti atoms on the Fe(100) surface is the greatest, facilitating the formation of T-zone structures with superior mechanical properties.