Combustion and passivation of nickel nanoparticles

Nanoscaled pyrophoric nickel powders were synthesized by the decomposition of nickel formate layers 1–3 mm thick in a flow of hydrogen at 209°C and then passivated in a flow of 0.6% oxygen + Ar for 2–10 min. The time of completion of passivation coincides with the time of beginning of cooling down of the sample during passivation.