Surface diffusion and phase transitions in electropositive overlayers

Surface diffusion (SD) is a phenomenon of particular importance in vacuum microelectronic devices whose characteristics are highly sensitive to microgeometry of electrodes and to distribution of adsorbed species on their surfaces. In this work we have investigated the correlation between the variation of SD rate of electropositive adsorbates (alkali, alkaline-earth and rare-earth metals) and phase transitions occurring in their overlayers with increasing coverage. Extremely strong phase effects in SD of such adsorbates have been found. Possible mechanisms of SD are discussed