Selective nanoparticle heating: another form of nonequilibrium in dusty plasmas.

Nanoparticles produced in low-temperature plasmas (LTPs) are often found with crystalline structure, which suggests rather high temperatures during synthesis. This even applies to particles of high-melting-point materials, which is surprising, because the gas temperature in LTPs is often close to room temperature and particles may reside in the plasma only for a few milliseconds. In this paper, we present a numerical study of nanoparticle heating in plasmas through energetic surface reactions. We find that, under realistic plasma conditions, particle temperatures can exceed the gas temperature by many hundreds of kelvins. However, as the particle temperature is highly unsteady, it is more reasonable to consider particle temperature distribution functions. The dependence of the particle temperature distribution on particle size and particle density in a dusty LTP is discussed.