Abstract. The CrNx (0 < x = N/Cr < 1) coatings on Mg alloy were prepared by DC reactive planar magnetron sputtering at a mixed atmosphere containing Ar and N2. The effects of N2 content and thickness on the CrNx coatings were characterized by the X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The experimental results …