First-principles investigation on the atomic structure and stability of a Pt monolayer on Fe(001)

We investigated the atomic structure and stability of a Pt monolayer on Fe(001) using spin-polarized density functional theory (DFT)-based total energy calculations. The results show that addition of a Pt monolayer on Fe substrate completely removes Fe(001) surface relaxation and induces minimal disordering of Fe atoms in the interior region in accordance with experimental findings. The stable distance between the Pt monolayer and the Fe substrate is 1.630 angstrom and the binding energy of Pt on Fe (per surface atom) is 2.00 eV. Comparison of such a binding energy with Pt-Pt binding in the first adjacent fcc Pt(001) layers shows that Pt binds more on Fe than with its corresponding pure metal slab. Such strong binding results in stabilization of the Pt monolayer on Fe(001) as verified by an increase in charge density within the Pt-Fe interface. Interestingly, addition of a Pt monolayer also induces enhancement of Fe-Fe interlayer binding in the interior region.