Formation of nitride thin films by electrochemical implantation

Formation of iron nitride films by electrochemical implantation has been investigated in LiCl-KCl-Li3N systems. Electrochemical formation of iron nitride thin films has been achieved according to the following manner. When an iron electrode is anodically polarized in an LiCl-KCl eutectic melt at 450 degrees C in which Li3N is dissolved, the electrochemical. implantation proceeds according to the reaction steps; N3- = N-ads + 3e xN + Fe = FeNx Anodically produced nitrogen atoms react with the outermost surface of electrode and diffuse into bulk of iron electrode to form iron nitride thin film. The main phase of obtained nitride layer was found to be an fcc-structured gamma'-Fe4N from XRD analysis. From XPS and EPMA results, it was confirmed that the nitride film consisted of an epsilon-Fe2N1-x layer with concentration gradient, a homogeneous gamma'-Fe4N layer and an alpha-Fe layer. It was shown that nitrogen concentration in the film and its thickness were controlled by changing the applied potential. It has turned out that Similar process was applicable to the electrochemical formation of cobalt nitride, aluminum nitride and Fe-Sm-N ternary nitride films.