Interatomic Auger analysis of the oxidation of thin Ba films

摘要: Abstract The oxidation and thermal desorption of evaporated Ba films on different substrates have been characterized using low energy interatomic AES techniques. films, which were deposited W〈100〉 (as well as Ir Os-W) varied from a fractional layer to ∼ 10 layers. Oxidation states, i.e. Ba: O x , ranged =0 ≈2. Comparison these data those actual impregnated cathodes allows one infer the thickness state cathodes. results indicate that active for “B-type” can be reproduced by near monolayer stoichiometric BaO W surface. density atoms (or atoms) in this “monolayer” should half based size consideration compared W. This was confirmed LEED. Measurements effusion compounds pores, substrate interaction evaporation substrate, ratio is not only stable configuration, but also has lowest work function (i.e. 2 eV). lowered because dipole formed adsorbed BaO. Studies electron interactions between (in agreement with surface plasmon results) more complete transfer exists than substrate. These are observation 2p states appear filled 6s valence electrons.