Rapid crystallization of electrohydrodynamically atomized ZrO2 thin films by laser annealing

This paper aims to provide a simple and rapid fabricating method for solution-based ZrO2 thin films. The ZrO2 thin film was firstly deposited on a 316L stainless steel substrate by electrohydrodynamic atomization. Then the crystallization process was carried out by a 4W Nd:YAG laser with a wavelength of 1064 nm. The morphology, structure and evolution of chemical bonds (Zr and O) were evaluated by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. After laser annealing, the O 1s (O-containing ions in ZrO2) fraction rose from 22.6% to 51.1%, and the principal tetragonal phase composition was obtained. The large temperature gradients that derived from the photothermal effect contribute to the fast crystallization during the laser treatments. The tribological and electrochemical corrosion experiments reveal that the laser crystallized films have significantly well wear and corrosion resistance, close to those of conventionally crystallized films. This fabricating method is simple, energy-saving and could achieve the spatially-resolved crystallization of films with a minimal temperature increase on the underlying substrates.