Interface stabilization of Fe/Al(0Â 0Â 1) films by Ti interlayers-an ab-initio DFT study

The stabilization of the growth of near-perfect Fe layers on Al(0 0 1) by the deposition of a Ti interface layer has been investigated using ab-initio density-functional method. We find that Ti deposition on Al(0 0 1) 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(0 0 1) 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.