Surface self-diffusion of iridium: Field electron emission study

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