Energy conversion and ignition of iron nanoparticles by flash

In the present study, Fe nanoparticles (NPs) can ignite when exposed to a conventional camera flash. The ignition process of Fe NPs was composed of the initial ignition stage with the maximum temperature level of 2000 K and the burning stage with temperature level of 800 K. The microstructure characterization indicated Fe NPs were oxidized to Fe 2 O 3 via the exposure-melt mechanism. It was found that more particle numbers per unit area can lead to lower minimum ignition energy which may be caused by the enhancement light energy absorption. The light energy absorbed from the flash was influenced by wavelengths but the conversion of Fe was only related to the packing mass.