Low-energy electron diffraction study of multilayer relaxation on a Pb{001} surface

Multilayer relaxation on clean Pb{001} has been determined by analysis of low-energy electron diffraction (LEED) intensity data collected from a sample at -140°C. The first interlayer spacing is compressed from the bulk value by 8%, the second interlayer spacing is expanded by 3.1%, and the third interlayer spacing is compressed by 3.0%. These results confirm the remarkably large first-interlayer contraction that was first observed on Pb{110} both by ion scattering and by LEED. The modified point-ion model, which was rather successful in predicting the magnitude of multilayer relaxation on several surfaces of fcc and bcc metals, fails to explain the behavior of Pb surfaces. © 1990 The American Physical Society.