Correlation of 3d transition metal carbide phase formation with 3d electrons by carbon ion implantation

A systematic study of carbide phase formation by carbon ion implantation showed NaCl type f.c.c. carbide formation in Ti, V and Cr, and hexagonal carbide formation in Fe, Co and Ni. No carbide formation was observed in the system Cu, Ag, Au and Zn. This indicates that 3d transition metal carbide phase formation by carbon ion implantation correlates with incomplete 3d shell electrons. The s shell electrons do not contribute. The electronic factor was further demonstrated in the structural alternation from f.c.c. in systems of Ti, V and Cr to hexagon in Fe, Co and Ni with increasing 3d electron concentration, which follows the Hume-Rothery rule.