The (2×2)p2mg and c(2×2n) structures induced by oxygen adsorption on Rh(110) have been examined by means of scanning tunneling microscopy. The real-space images show the glide and centered symmetry required by the diffraction patterns, as well as substrate reconstruction. In addition, a metastable (6×2) structure and a number of defects have been identified and characterized, including an antiphase domain wall in the (2×2) structure. Where a step defect separates two c(2×8) domains, they tend to adopt a specific morphological relationship.

• Received 25 October 1993

DOI:https://doi.org/10.1103/PhysRevB.49.5585