A procedure was described which allows routine preparation of clean unreconstructed 1 x 1 surface structures of Ir(100) single crystal surfaces. Evidence was given that those unreconstructed surfaces were not stabilized by detectable amounts of impurities. From UPS it was suggested that upon reconstruction a reorganisation within the Ir d-bands take place. By comparison with photo-emission from a Ir(111) surface there was strong evidence that the hexagonal overlayer model was a correct description of the reconstructed 5 x 1 surface. A 1 x 1 surface structure transformed to the well known 5 x 1 structure with temperature-dependent kinetics, the 1 x 1 structure being stable below ≈800K. An analysis of the reconstruction kinetics led to an apparent activation energy of 20kcal/mole for the 1 x 1 to 5 x 1 structure conversion. A determination of the oxygen sticking coefficient on both surface structures demonstrate marked chemical differences between those surfaces.

Preparation of Ir(100)-1 x 1 Surface Structures by Surface Reactions and its Reconstruction Kinetics as Determined with Low-Energy Electron Diffraction, UPS and Work Function Measurements. J.Küppers, H.Michel: Applications of Surface Science, 1979, 3[2], 179-95