Nitriding of zirconium in a radio frequency discharge

The nitriding of zirconium in a nitrogen or nitrogen-hydrogen plasma obtained from a radio frequency discharge was studied. Power was supplied from an inductively coupled 13.56 MHz 500 W generator. The reaction kinetics obeyed a parabolic relationship and the reaction constants were 10-12-10-13 g2cm-4s-1 under various conditions. The surface of the nitrided metal was hardened by the formation of ZrN. The product was found to be superconducting below 10.1 K. (Auth.)