Ln(2)NiO(4+delta) (Ln = La, Pr, Nd) coatings deposited by reactive magnetron sputtering as cathode material for intermediate temperature solid oxide fuel cell

This work focuses on the comparison of Ln-Ni-O coatings (Ln = La, Nd, Pr) deposited by reactive magnetron sputtering using Plasma Emission Monitoring (PEM) which allows high deposition rate. Each layer is deposited by different steps. The optimal regulation setpoint for oxide rare-earth deposition is determined and then the current dissipated on the nickel target is adjusted to obtain the convenient Ln/Ni ratio and to achieve the K2NiF4 structure. After an appropriate annealing treatment, all coatings exhibit crystalline structures, which depend on the Ln/Ni ratio. Due to the instability of Pr2NiO4 structure at intermediate temperatures, the crystallization step of praseodymium nickelate is performed at higher temperature than the other materials. This further thermal treatment implies a more porous structure. Each coating exhibits interesting properties. Electrical and electrochemical characterizations performed on these deposits prove better properties of the praseodymium nickelate coating. (C) 2018 Elsevier Ltd. All rights reserved.