Multilayer relaxation of a Pb{111} surface

Multilayer relaxation on clean Pb{111} has been determined by analysis of low-energy electron diffraction intensity data collected from a sample at -140°C. The first interlayer spacing is compressed from the bulk value (2.844) by (3.5±1)%, the second interlayer spacing is expanded by (0.5±1.4)%, and the third interlayer spacing is expanded by (1.6±1.8)%. These results are consistent with the observations made on Pb{110} and Pb{001} that Pb surfaces exhibit structure relaxations markedly larger than on surfaces of other fcc metals investigated to date. © 1991 The American Physical Society.