We have studied nucleation and growth characteristics of diamond on nickel with AlN buffer layers. The diamond deposits on partially filled 3‐dshell transition metals such as Ni, Fe, and Co usually result in the formation of interposing graphite layers which cause poor adhesion of diamond overlayers. To minimize and preferably eliminate the formation of the interposing graphite layer, we coated nickel substrate with ∼1000 A˚ thick AlN layer by using pulsed laser deposition and subsequently, subjected them to diamond deposition by hot filament chemical vapor deposition method. It is found that the aluminum nitride layer plays a crucial role in limiting carbon diffusion and inhibiting the formation of graphitic carbon and simultaneously enhancing the nucleation and adhesion of diamond phase. ©1995 American Institute of Physics.