Photonic Sintering of Oxide Ceramic Films: Effect of Colored FexOy Nanoparticle Pigments

Alumina and zirconia thin films modified with colored nano-FexOy pigments were sintered by the flash-lamp-annealing method. We selected a nano alpha-Al2O3 and micron alpha-Al2O3 bimodal mixture as the base precursor material, and we doped it with 5 vol% of FexOy red/brown/black/yellow pigments. The coatings were deposited from nanoparticle dispersions both on glass and on flexible metal foil. The characteristics of the thin films obtained with the use of various additives were compared, including the surface morphologies, optical properties, crystallinities, and structures. Flash lamp annealing was applied with the maximum total energy density of 130 J/cm(2) and an overall annealing time of 7 s. Based on the simulated temperature profiles and electron-microscopy results, a maximum annealing temperature of 1850 degrees C was reached for the red Al2O3: Fe2O3 ceramic film. The results show that red alpha-Al2O3 pigments allow for the achievement of maximum layer absorption, which is effective for flash lamp sintering. It was also possible to use the selected red alpha-Al2O3 particles for the flash-lamp-assisted sintering of ZrO2 on a 30 mu m-thin flexible stainless-steel substrate.