Abstract :
Adsorption and desorption of oxygen on a tungsten tip were studied by the FEM method. From measurements of work function changes of a tungsten tip at 300 K during the adsorption of oxygen, two adsorption states, i.e., β2 and β1 adsorption states were obtained. Work function changes by heating of tips at the saturation of β2 and the saturation of β1 were measured as a function of heating temperature, and some FEM pattern changes were photographed. These results were discussed by a model, and the β1 adsorption state was interpreted to be due to the adsorption on the layers below the outermost layers of crystallographic planes.
