In this work, thin films of Li x NiO y were deposited by rf reactive magnetron sputtering, from a LiNiO2 target. The composition of the films was analyzed by Rutherford backscattering spectroscopy. The electronic structure was analyzed by photoelectron spectroscopy, using either X-ray (Al Kα) or synchrotron light (120eV). X-ray diffraction showed a clear presence of Li2CO3 in the target material, after some deposition runs. The presence of superficial lithium carbonate was also evidenced, for all films.