Auger electron spectroscopic studies of the water vapour adsorption on the (100) surface of austenitic chromium-nickel steel

The water vapour adsorption on the (100) surface of chromium-nickel steel was studied by Auger electron spectroscopy (AES) in the temperature range of 300 K to 700 K at water vapour pressures of 13.3 μPa to 133 mPa. The water vapour adsorption goes on more slowly than the oxygen adsorption under the same conditions. The measured kinetic isotherms may be described by logarithmic time laws as they are typical of the adsorption on inhomogeneous surfaces. With rising temperature of the samples the rate of adsorption as well as the quantity of fragments of the water molecule adsorbed during saturation state increases, i.e. the adsorption is activated. By means of the measured adsorption isotherms it may be concluded that a dissociative adsorption takes place.