Time-resolved laser-induced incandescence on metal nanoparticles: effect of nanoparticle aggregation and sintering

This work examines the excessive absorption and anomalous cooling phenomena reported in laser-induced incandescence measurements on metal nanoparticles by considering effects of aggregate structure sintering. Experimental investigations are conducted iron molybdenum aerosols, which have different melting points, thus respond differently to laser pulse. Although aggregation enhances cross-section allows for higher peak temperatures, this enhancement does not fully explain observed absorption. Furthermore, as aggregates refractory metals such cool, they may sinter through gradual grain boundary diffusion; change alters their cross-section, manifesting a rapid drop pyrometric temperature, could metal.