Temperature dependent structure of clean Ag(110) studied by medium energy ion scattering

Medium energy ion scattering has been used to investigate the surface structure of clean Ag(110) in the temperature range 300-1000 K. Using ion shadowing and blocking, together with Monte Carlo simulations, multilayer relaxations are determined up to 600 K. At room temperature, the familiar oscillatory contraction/expansion is observed. As the temperature increases to 600 K, the first-to-second layer contraction gradually disappears, while the second-to-third layer expansion becomes a contraction. A detailed analysis at room temperature reveals an anisotropy in the vibrational amplitudes of the first two layers. Investigation of the ion scattering intensity versus temperature and the backscattered ion energy spectra gives evidence that the surface begins to disorder beyond a temperature of 680 +/- 35 K. A complete disordered layer results by 1000 K. The experimental results are compared with theoretical results based on molecular dynamics simulations. (C) 1998 Elsevier Science B.V. All rights reserved.