Growth of polycrystalline Pr2NiO4+δ coating on alumina substrate by RF magnetron co-sputtering from composite targets

•Pr2NiO4+δ coatings deposited by RF magnetron co-sputtering•Crystallization kinetic studied by X-ray diffraction versus temperature•SEM and AFM observations showed dense and rough microstructure•Normal spectral emittance reaches to ε = 0.8 at 794 °C in the opaque zone.

Polycrystalline Pr2NiO4+δ coatings have been deposited on alumina substrates at room temperature by RF magnetron co-sputtering from Pr and Ni metallic composite target. The mixed target's area and the sputtering conditions were optimized to reach an atomic ratio Pr/Ni of 2. A subsequent annealing, at 1050–1100 °C, allowed obtaining Pr2NiO4+δ phase after in situ high temperature x-ray diffraction study performed on as-deposited film. Microstructural analyses (SEM and AFM) revealed dense and rough microstructure. Normal spectral emittance measurements performed at 794 °C in the spectral range 400–5000 cm-1 showed an emissivity of ε ≈ 0.8.