Étude de l'adsorption de l'oxygène sur ruban de rhénium par mesure des variations du travail d'extraction électronique

Adsorption and work function changes have been followed on a recrystallized rhenium ribbon preferentially oriented with (0001) plane parallel to the surface] in an ultrahigh vacuum apparatus. Gas pressure was monitored by mass spectrometry and work function variations measured with the diode method in the retarding potential range, using an electron gun. Despite changes in saturation coverages, work function differences at saturation, and sticking coefficient with the adsorption temperature of the sample, curves giving the surface potential with coverage are characterized by a common part till a critical coverage ($\text{5 × 10}{}^{14}\text{atoms}\text{cm}{}^2$), in the 300–850 K range. Comparison with LEED, thermal desorption and electron induced desorption results of the literature is in agreement with an adsorption induced surface rearrangement, above this critical coverage.