Field emission microscopy studies and very high-resolution Auger electron spectroscopy analyses of platinum field-emitter surfaces show that P, Si, and S impurities strongly segregate to the {100} areas, and that Si stabilizes the non-equilibrium {012} planes. Auger spectra demonstrate the difficulty of detecting Si and S impurities on Pt because of peak-overlap problems at 92 and 152eV, respectively. Evidence was presented which suggests that these impurities were largely overlooked in Pt{100} reconstruction studies.

Surface-Impurity Segregation on Pt and Its Potential Role in the Reconstruction of Pt{100}. M.Mundschau, R.Vanselow: Physical Review Letters, 1984, 53, 1084-7