Melting of clusters approaching 0D

Abstract

Recently, new experiments have allowed us to understand the melting scenario of very small crystals. Down to sizes of 5–8 nm, surface melting amplified by curvature effects is observed; the melting process is initially continuous and reversible (first-order transition with critical phenomena due to confinement), When the inner solid core reaches a critical radius r _m, final melting occurs discontinuously and irreversibly. For clusters of sizes smaller than 5–8 nm, surface melting disappears and the inciting process is discontinuous.

Experiments yielding new information will be discussed for the different size ranges of the clusters and compared with models of melting taking surface melting into account. Issues requiring clarification will be stressed, particularly the problem of the limit (if any) of the lowering of the melting temperature.