A New Method for Preparation of Nanocrystalline Molybdenum Nitride

Nanocrystalline molybdenum nitride （γ-Mo2N） with the cubic structure is prepared by the direct-current arc discharge method in N2 gas, using metal Mo or W rod as a cathode. The x-ray diffraction （XRD） and transmission electron microscopy （TEM） are used to characterize the product. It is found that the conversion of Mo to γ-Mo2N and affinity of Mo to N2 are determined by the nitrogen pressure. Moreover, we compare the effect of Mo and W rod as a cathode for preparing γ-Mo2N. The average size of γ-Mo2N particles is about 5 nm. The rapid quenching mechanism can be used to explain the formation of nanocrystalline γ-Mo2N.