XPS STUDIES OF THE STABILITY AND REACTIVITY OF THIN-FILMS OF OXIDIZED ZIRCONIUM

X-ray photoelectron spectroscopy (XPS) has been used to characterize thin films formed by the deposition of zirconium on to gold foil. With deposition rates of the order of 1 angstrom min-1, in the presence of an atmosphere of 10(-9) mbar H2O, the film has an outer region Of ZrO2 and inner regions of a lower oxidation state material, ZrO(x), and Zr-Au alloy. Initially both ZrO(x) and Zr-Au alloy are oxidized by either H2O or O2 at 300-degrees-C, although this process is hindered as the ZrO2 layer gets thicker. However, even with the protective oxide layer, heating in 5 x 10(-7) mbar D2 (with a partial pressure of 10(-9) mbar H2O) can convert ZrO(x) to ZrO2, a reaction apparently facilitated by migrating D atoms.