FORMATION AND DECOMPOSITION OF THIN RHODIUM OXIDE-FILMS

Interaction of 02 with Rh(poly) and Rh(100) has been studied by Auger Electron Spectroscopy and thermal desorption method at 02 pressures of 10(-5)-10(3) Pa and at 400-1600 K. At P(O2) < 10(-5) Pa chemisorption of O2 occurs, at P(O2) = 10(-5)-10(-1) Pa surface oxides are formed, at P(O2) > 1.0 Pa a bulk Rh2O3 oxide starts to grow. The growth of rho dium oxide film proceeds via the Cabrera-Mott mechanism. Its decomposi tion occurs via a mechanism including electron transfer across the oxi de film, O2 desorption from the surface layer and rearrangement of the oxide layer.