TEMPERATURE-PROGRAMMED DESORPTION STUDY ON THE OUTGASSING PROCESS FROM ALUMINUM SURFACE

Temperature-programmed desorption (TPD) has been applied for the first time to a study of time-dependent outgassing process from a metal sur face. The TPD area which corresponds to the adsorbate coverage, decrea sed with the pumping time t, whose temporal dependence t(-beta(1-beta) ) quantitatively agreed well with what was predicted by the Freundlich adsorption isotherm and Mizuno-Horikoshi theory. The H2O-TPD spectra consist of a peak at around 90 degrees C in which the desorption proce eds from lower temperatures towards higher temperatures, and a broad b ackground appearing at 100 < T < 500 degrees C, in :which the desorpti on proceeds rather uniformly irrespective of the desorption temperatur e. The presence of the latter suggests an unidentified desorption mode from the metal surface. Copyright (C) 1996 Elsevier Science Ltd.