MISSING-ROW CONTRACTIVE RECONSTRUCTION ON AU(311)

All the low-index surfaces of gold are known to reconstruct, and their vicinals often exhibit magic orientations. The (311) orientation lies in between (100) and (111), and can be regarded as either a (111) or (100) vicinal with a very high step density, or as a flat open surface . In view of rather puzzling reconstructions observed experimentally [ (1 x 4), (1 x 5), (1 x 6)], we have undertaken a structural study of A u(311) using the glue model and molecular-dynamics-based simulated ann ealing. The optical geometry is a (1 x 5) missing-row structure with ( 111) and reconstructed (100) microfacets, and an alternation of (1 x 2 ) and (1 x 3) hills. An extra atomic row is present on (1 x 3) hills t o optimize packing. The experimentally observed disappearance of the r econstruction between 700 and 750 K is probably associated with an ord er-disorder transition similar to that of Au(110).