Abstract: The influence of mass flow of reactive gas on the composition and optical constants of deposited
NiCrO_x thin films was investigated. The results obtained show that NiCr target exhibits a poisoning phenomenon as O₂ flow rate
increased to a certain value during the reactive sputtering process. It is possible to deposit near transparent, dielectric thin films
as well as the non-transparent, absorbing thin films. The study of optical constants of the thin films deposited at different oxygen flow rate
may be applied to the development of solar selective surface.

Key words: magnetron reactive sputtering, NiCrO_x thin films, optical constants, solar selective surface