Quantitative structural analysis of fcc Fe(2×1) on Cu(001): A medium-energy ion-scattering study

The detailed structure of a 6-ML Fe film grown epitaxially at 310 K on a Cu(001) substrate was determined by high-resolution medium-energy ion scattering through comparisons with Monte Carlo simulations of the ion-scattering experiment. The observation of excess ion scattering from the Cu substrate atoms indicates that the lattice parameter of the Fe film deviates from the Cu lattice constant, i.e., the Fe film grows nonpseudomorphically. The Fe film is ordered fcc and has a reconstructed surface layer in the form of atom row glide along [110] directions with an expansion of the surface atom layer. Improved agreement between the ion-scattering simulation and the experimental data is obtained when the Fe lattice is rotated by about 1.2° relative to the Cu substrate. © 1995 The American Physical Society.