Sputter Power Influenced Structural, Electrical, and Optical Behaviour of Nanocrystalline CuNiO₂ Films Formed by RF Magnetron Sputtering

Copper nickel oxide (CuNiO₂) films were deposited on glass and silicon substrates using RF magnetron sputtering of equimolar Cu₅₀Ni₅₀ alloy target at different sputter powers in the range of 3.1–6.1 W/cm². The effect of sputter power on the chemical composition, crystallographic structure, chemical binding configuration, surface morphology, and electrical and optical properties of CuNiO₂ films was investigated. The films formed at sputter power of 5.1 W/cm² were of nearly stoichiometric CuNiO₂. Fourier transform infrared spectroscopic studies indicated the presence of the characteristic vibrational bands of copper nickel oxide. The nanocrystalline CuNiO₂ films were formed with the increase in grain size from 75 to 120 nm as the sputter power increased from 3.1 to 5.1 W/cm². The stoichiometric CuNiO₂ films formed at sputter power of 5.1 W/cm² exhibited electrical resistivity of 27 Ωcm, Hall mobility of 21 cm²/Vsec, and optical bandgap of 1.93 eV.