Surface melting in nanoparticles and nanosystems. 1. regularities and mechanisms of surface melting of macroscopic phases and nanoparticles

Being the first part of a two-part series, published in this issue of the journal, this paper combines a brief overview of theoretical and experimental studies, as well as the results of atomistic simulations of surface melting in bulk bodies and nanoparticles with presentation of our own molecular dynamics results. We have studied the patterns and mechanisms of surface melting in metal nanoparticles (gold, silver, copper, lead and nickel). The patterns and mechanisms of this phenomenon were studied in most detail on gold and silver nanoparticles. It has been established that the effect of surface premelting is characteristic for nanoparticles of all the above metals, although with decreasing particle size this effect manifests itself to a lesser extent. In addition, our molecular dynamics results do not confirm theoretical predictions of some authors about the existence of a quite definite characteristic (critical) radius of nanoparticles, below which the effect of surface melting is completely absent.