Deposition of cerium oxide thin films by reactive magnetron sputtering for the development of corrosion protective coatings

•Cerium oxide thin films were synthesized by reactive magnetron sputtering on Al substrates.•Deposition parameters allowed to vary chemistry and microstructure of the films.•Reinforcement of the barrier properties versus immersion time was observed.•It is associated with interaction between alumina and cerium oxide film in the electrolyte. As an alternative to chromate based coatings cerium oxide thin films were deposited by magnetron sputtering on Al clad 2024 alloy in order to evaluate their corrosion protection potential. Varying plasma properties by modifying O2 content during deposition allowed to affect the chemistry and microstructure of the synthesized films. The electrochemical characterization showed that specific self-healing mechanisms are suspected for the samples deposited with the highest amount of oxygen. Those mechanisms, leading to the reinforcement of barrier properties versus immersion time in NaCl solution, are associated with the interaction between alumina and cerium oxide film in the presence of electrolyte.