SURFACE SELF-DIFFUSION OF IRIDIUM: FIELD ELECTRON EMISSION STUDY

G. Antczak, M. Błaszczyszyn and R. Błaszczyszyn Institute of Experimental Physics, University of Wrocław, Pl. M. Borna 9, 50-204 Wrocław, Poland

Received: May 18, 2000; revised version July 17, 2000

The self-diffusion of iridium was studied by means of field electron microscopy. The measurements, based on the well-known process of surface build-up, were carried out under the UHV conditions within the temperature range of 790-935K. The activation energy for the diffusion was determined to be equal to 2.10+-0.10eV/atom (48.4+-2.3kcal/mol). This value is compared with activation energies for self-diffusion on other metal surfaces, as well as with those for self-diffusion of single iridium atoms and clusters on iridium, known from the field ion microscopy measurements.

PACS numbers: 61.16.-d, 68.35.Fx, 68.55.-a, 68.90.+g