SCANNING-TUNNELING-MICROSCOPY STUDY OF THE OXYGEN-INDUCED RECONSTRUCTION OF RH(110)

Scanning-tunneling microscopy has been used to investigate the oxygen- induced c (2 X 2n) (n = 3, 4, and 5) structures on Rh(110). The result s show that oxygen induces a (I X n) reconstruction of the Rh substrat e with every nth close-packed row along the [110BAR] direction missing . This is in contrast to other oxygen-induced reconstructions of face- centered-cubic (110) surfaces where [001] rows are missing, and implie s a different driving mechanism for the present case. On the basis of the images and the symmetry of the diffraction patterns, structural mo dels are proposed.