Intermixing at Pb/Si(111) and Pb/Si(001) interfaces studied with electron-energy-loss spectroscopy

Pb/Si interfaces prepared by deposition of Pb onto the clean Si(111)7×{}7 and Si(001)2×{}1 surfaces, as well as oxygen-contaminated Pb/Si interfaces prepared by deposition of Pb onto the oxygen-contaminated Si(111)7×{}7 and Si(001)2×{}1 surfaces, have been studied with electron-energy-loss spectroscopy in conjunction with low-energy electron diffraction and Auger electron spectroscopy. The results show that, in contrast with its generally accepted properties, Pb intermixes strongly with Si at the Pb/Si(111) and Pb/Si(001) interfaces, forming a unique intermixed interfacial phase. However, at the oxygen-contaminated interfaces no evidence of such intermixing could be found.