Atomic-Scale Investigation on the Ti/Fe(001) Interface Structure: Molecular Dynamics Simulations and Ab initio Calculations

Abstract

The structure dependent magnetism and intermixing characteristics of Ti/Fe(001) thin films were investigated using molecular dynamics simulations and ab initio calculations. Through density functional theory based ab initio calculations, sharply decreased demagnetization energy of Fe(001) substrate by the interface intermixing was observed. The intermixing at the Ti/Fe(001) interface was limited within only the topmost layer of the Fe(001) substrate at temperatures ranging from 300 to 600 K with incident energies of a Ti atom from 0.1 to 5 eV. Both the high deposition temperature and the high incident energy of the Ti adatom inproved the surface smoothness of the deposited Ti films. The elevated temperature significantly increased the amount of Ti/Fe interface intermixing, while the incident energy dependency was negligible. The extremely low atomic intermixing ratio and short diffusion length of Ti/Fe system compared to other transition metal thin films could be explained by comparing the local acceleration and incorporation energy barrier effects.