Three dimensional arrays of hollow gadolinia-doped ceria microspheres prepared by r.f. magnetron sputtering employing PMMA microsphere templates

Preparation of macroporous gadolinia-doped ceria (CGO) films was attempted by r.f. magnetron sputtering. A polymethylmethacrylate (PMMA) microsphere film was fabricated as a template on a Pt-coated silicon substrate by dripping a PMMA microsphere aqueous dispersion onto the substrate. CGO was deposited onto the PMMA microspheres by sputtering; the PMMA microspheres were found to shrink during the sputtering, and thus the CGO also coated the surface of PMMA microspheres beneath the top layer of the film. Films (ca. 1.5 mu m thick) consisting of three dimensional arrays of hollow CGO microspheres (ca. 700 nm in diameter) with large porosity were obtained after annealing the CGO/PMMA microsphere composite film.