Improved resolution in HREELS using maximum-entropy deconvolution: CO on PtxNi1−x(111)

Abstract High-resolution electron energy loss spectroscopy (HREELS) has been used to study stretch vibrations of CO chemisorbed at low coverage on Pt x Ni 1− x (111). Bayesian probability theory along with the entropic prior (Maxent) has been employed to deconvolve the apparatus function and to improve the apparent energy resolution. Maxent has proven very successful in a wide range of inversion problems. Here the resolution enhancement enables the positions of CO on the PtNi surface to be identified. It appears that CO is predominantly on top of Ni with the Ni atoms coordinated threefold laterally and with Ni in linear chains or on top of Pt. Furthermore, the ratio of the Pt to the Ni peak is used to study the dependence of the Pt concentration in the first layer on the annealing temperature.