A model of a reconstructed vanadium single-crystal (111) surface was proposed on the basis of low-energy electron diffraction observations of the clean surface formed in the (√3 x √3)R30° structure. The observation was reported, of the reconstructed V(111) surface in real space, using an ultra-high vacuum scanning tunnelling microscope with which it was possible to control precisely the temperature of a sample even at temperatures of up to 1500K. A main cleaning procedure was to anneal the sample for 20h at over 1300K in ultra-high vacuum and to flash it at 1500K many times immediately prior to the scanning tunnelling microscopy measurement. It was possible to interpret the observed scanning tunnelling microscopy images reasonably using a previously proposed model for the reconstructed surface. In the scanning tunnelling microscopic images, however, unexpected step structures were observed on the (111) surface that could not be found in the low-energy electron diffraction measurements.

Low-Energy Electron Diffraction and Scanning Tunnelling Microscopy Study on the Reconstruction of the Vanadium (111) Surface. K.Nakayama, T.Sato, S.Usami, M.Iwatsuki: Japanese Journal of Applied Physics, 1995, 34, 589-94