抄録
Chromium nitride films of various composition were deposited on glass substrates by r.f. reactive ion plating, and the deposition rate, along with the structure and the corrosion resistance of the films were investigated: At a constant nitrogen pressure the deposition rate increases, but the nitrogen content of the nitride film tends to decrease with an increase in the electron beam current used for evaporating chromium. X-ray diffraction shows that the film is a solid-solution of Cr and N (α-Cr) at a current of 100 mA, a mixture of Cr2N and CrN at 60 mA, and a single phase of CrN at 10∼50 mA. Decrease in the current leads to a transformation in the film structure: a structured film changes to a nearly amorphous, dense film with a smooth surface, and there is a great improvement in the corrosion resistance. The Cr and α-Cr film are rapidly corroded in 1 kmol·m−3 H2SO4 at 373 K, while the single phase of CrN hardly corrodes at all. In a mixture of Cr2N and CrN, Cr2N is selectively corroded, and the amount of dissolved chromium is about two orders of magnitude larger than that for the single phase of CrN. The films deposited with a low electron beam current are bent due to the difference in thermal expansion between the film and substrate, and some of the films peel off during the corrosion test.
