THE LIFTING OF THE PT(100) SURFACE RECONSTRUCTION BY NO ADSORPTION

It has been known for many years that the Pt{100} surface reconstructs to give a quasi-hexagonal outermost layer, known as the (hex) phase and that the reconstruction can be lifted by chemisorption to give the 'truncated bulk', or (1 × 1), structure. We show using ir reflection-absorption spectroscopy that at sufficiently low temperature and low coverage NO can adsorb on the (hex) surface without inducing the phase transition. At increased temperatures, the maximum NO coverage that still retains the (hex) phase decreases, until at 200 K and above adsorption immediately lifts the reconstruction. © 1990 Pergamon Press plc.