Production Strategies of TiN_x Coatings via Reactive High Power Impulse Magnetron Sputtering for Selective H₂...

This scientific work aims to optimize the preparation of titanium nitride coatings for selective H₂ separation using the Reactive High Power Impulse Magnetron Sputtering technology (RHiPIMS). Currently, nitride-based thin films are considered promising membranes for hydrogen. The first series of TiN_x/Si test samples were developed while changing the reactive gas percentage (N₂%) during the process. Obtained coatings were extensively characterized in terms of morphology, composition, and microstructure. A 500 nm thick, dense TiN_x coating was then deposited on a porous alumina substrate and widely investigated. Moreover, the as-prepared TiN_x films were heat-treated in an atmosphere containing hydrogen in order to prove their chemical and structural stability; which revealed to be promising. This study highlighted how the RHiPIMS method permits fine control of the grown layer's stoichiometry and microstructure. Moreover, it pointed out the need for a protective layer to prevent surface oxidation of the nitride membrane by air and the necessity to deepen the study of TiN_x/alumina interface in order to improve film/substrate adhesion.