Size and shape of supported zirconia nanoparticles determined by x-ray photoelectron spectroscopy.

The initial stages of growth of zirconia nanoparticles deposited on SiO₂, Y₂O₃, and CeO₂ substrates have been studied by the x-ray photoelectron spectroscopy peak shape analysis. ZrO₂ was deposited by plasma decomposition of a volatile Zr(OtBu)₄ precursor. The electronic interactions at each particular interface formed have been followed by means of the modified Auger parameter of the deposited Zr cations. They were quantified by means of Wagner plots and the chemical state vectors of the systems. The observed changes in these local electronic probes as the amount of deposit was increased have been correlated to the particular ZrO₂ nanostructures identified on each substrate considered. A Volmer-Weber (islands) growth mechanism has been found for all the substrates considered. Moreover, clear indications have been found of a columnar growth for the case of ZrO₂ deposited on SiO₂. [ABSTRACT FROM AUTHOR]