Interface stabilization of Fe/Al(001) films by Ti interlayers—an ab-initio DFT study

The stabilization of the growth of near-perfect Fe layers on Al(001) by the deposition of a Ti interface layer has been investigated using ab-initio density-functional method. We find that Ti deposition on Al(001) leads to the formation of an Al3Ti surface alloy with strong Al–Ti and Ti–Ti bonds and hence an increased stiffness of the surface. As a consequence, a barrier against diffusion of Fe atoms into the Al substrate is formed. At a complete monolayer coverage of the Al3Ti/Al(001) surface, however, a subsurface position of the Fe layer is again energetically preferred. This demonstrates that the stabilizing effects of the Ti interfactant is of kinetic origin and vanishes at elevated temperatures.