Low-energy electron diffraction study of the thermal expansion of Ag(111)

The temperature dependence of the first three interlayer distances of the A g(lll) surface was studied by low-energy electron diffraction (LEED) over t he temperature range 128-723 K. The first three interlayer spacings and the effective Debye temperatures were extracted from the LEED analysis. At the lowest temperature, the first two interlayer spacings are slightly (0.5%) contracted. All three interlayer spacings increase with temperature. finall y reaching expansions relative to the bulk of about 0.8% at the highest tem perature studied. The effective surface Debye temperature is lowest for the outermost layer, increasing toward the bulk value for successive layers. ( C) 2000 Elsevier Science B.V. All rights reserved.