XPS STUDY OF PD PARTICLE GROWTH ON DIFFERENT ALUMINA SURFACES

X-ray Photoelectron spectroscopy (XPS) was used to investigate the Pd particle formation on Al2O3 substrates. Palladium was deposited step b y step in situ using an electron beam evaporator on single crystalline alumina specimens which had been cleaned by heating in air. The (0001 ), (1-102) and (11-20) orientations of alumina were used for Pd deposi tion with no further treatment. In addition, the (0001) and (1-102) su bstrates were also Ar+ ion sputtered before deposition, to change the surface stoichiometry and order. The Pd growth process was monitored b y means of the modified Auger parameter and the Full Width at Half Max imum of the Pd3d(5/2) peak. The results obtained on the different subs trates are compared and the influence of the substrate on the Pd parti cle growth is discussed. (C) 1998 Elsevier Science Ltd. All rights res erved.