The Nio as single-phase was exclusively synthesized under fuel-lean ratios. It is attributed to due the fact that those reactions were carried out under an oxidant condition. In the case of fuel-rich ratios, the reducing condition allowed to grow the nickel metallic phase. The amount of fuel employed definitely plays an important, perhaps crucial role, in the determination of the properties of Ni synthesized by solution combustion synthesis. Crystallite sizes are presented in Fig. 5. The lowest crystallite sizes were obtained under lean glycine-to-nitrate ratios. It is attributed to a decrease in flame temperature, which c difficult growth. case of formulation the powder synthesized was not nanometric. There is a correlation between the increase in crystallite size as a function o fuel content in the case of glycine-nitrate combustion. Many authors have already observed this relationship [11,12]