Scanning tunnelling microscopy and low-energy electron diffraction of clean Ir(110) reveal a surprising novel route for the (110) surface of a fcc metal to stabilize its surface configuration. The Ir(110) surface was characterized by mesoscopic grooves of several 100nm in length along the direction of the close-packed rows and depths between 0.5 and 1.5nm. Extended (331) facets on the walls and local unreconstructed (110) structures on the ridges were observed. Ir(110) obviously strongly differs from Au(110) and Pt(110), which exhibited (1 x 2) missing-row-type reconstructions with (111) microfacets.

New Aspects on the Ir(110) Reconstruction - Surface Stabilization on Mesoscopic Scale via (331) Facets. R.Koch, M.Borbonus, O.Haase, K.H.Rieder: Physical Review Letters, 1991, 67, 3416-9