Al Intermediate Oxidation-States Observed by Core-Level Photoemission Spectroscopy
Aluminum oxidation states in stoichiometric or substoichiometric configuration are studied by core level photoemission spectroscopy on different substrates (SiO2, graphite). They are compared with recent results reported for the interface Si-Al-n+O. Three Al oxidation states have been identified and their space distribution (binding energy, intensity, and width) is determined in the region from the interface with the substrate up to the surface of a thick overlayer. The Al-2+O-- intermediate oxidation state is shown to be confined at the interface; on the contrary, the Al1+-O oxidation state and the stoichiometric oxide (alumina) are present beyond the interface region. From the attenuation of the substrate core level peak, the deposition morphology and the attenuation length of the photoelectrons have been deduced. (C) 1995 American Institute of Physics.
Acad sinica,inst phys,taipei,taiwan. univ wisconsin,ctr synchrotron radiat,madison,wi 53589. ecole polytech fed lausanne,ph ecublens,inst phys appl,ch-1015 lausanne,switzerland. Faraci, g, univ catania,ist nazl fis mat,dipartimento fis,corso italia 57,i-95129 catania,italy.
ISI Document Delivery No.: RU953
Record created on 2006-10-03, modified on 2016-08-08