Structural and cathodoluminiscent properties of Zr0.95Ce0.05O2 nanopowders prepared by sol–gel and template methods

Nanopowders of Zr0.95Ce0.05O2 composition have been prepared by a standard Pechini-type sol–gel process and by means of a colloidal crystal template approach. In the latter method, inverse opal Zr0.95Ce0.05O2 powders were fabricated employing poly(methyl methacrylate) (PMMA) colloidal crystals as a template. The effects of the two different synthesis routes on the structure and microstructural characteristics of the prepared nanopowders were evaluated by X-ray diffraction and scanning electron microscopy. For both preparation routes, the X-ray diffraction analysis has shown that a tetragonal fluorite structure is formed with a crystallite size of ∼35–40 nm. The scanning electron microscopy measurements indicate that the powder obtained by the sol–gel Pechini-type process is comprised of nanoparticles that are arranged in agglomerates with shape and size relatively uniform whereas the inverse opal Zr0.95Ce0.05O2 nanopowders exhibit the formation of macropores with a mean size of ∼100 nm. The cathodoluminescence spectra of the prepared Zr0.95Ce0.05O2 nanomaterials have been measured in the 300–800 nm wavelength range. The powder prepared by sol–gel method yields a broad emission band centered at 482 nm whereas the emission from the inverse opal preparation is considerably less intense.