Study of Adsorption of Gases on Solids in the High Vacuum Range

Abstract

Abstract : Investigation of the interaction of N2 with a hot W filament showed that a chemical pumping effect occurs and that the magnitude of this effect varied with temperature. The sticking probability of N2 on W was measured as a function of surface coverage. The data at lower coverages represents the temperature variation in the sticking probability. The surface concentration of N2 at saturation varied with the equilibrium pressure. In studies of the adsorption of O2 on Mo, the sticking probability and Mo work function changes were calculated as a function of O2 surface coverage. For the adsorption of CO on Mo, the calculated value of initial sticking probability and total number of adsorbed molecules are considerably smaller than expected, due to reversible sorption processes. Following the adsorption of CO on polycrystalline W, the subsequent introduction of O2 results in an increase in work function (from 5.2 eV to 6.4 eV) which indicates that a surface previously saturated with CO will not prevent the subsequent adsorption of O2. The retarding field technique for measuring work functions was applied to a silicon semiconductor surface. (Author)