Phase behavior of ionic clusters down to nanoscale. A review of recent work

Abstract

ABSTRACT:As finding an exact and manageable partition function for nanoclusters is a desirable but, so far, unattainable task, approximated treatments are proposed to explain and predict phase changes and phase coexistence at these size scales. In this article, a review of those approaches is presented, mainly focusing the authors work on the subject. The foundations and limitations of the proposed models are discussed and perspectives for extended treatments are given. The discussions are illustrated with new molecular dynamics simulations of unconstrained NaI and NaCl clusters.

Nanoscale thermal stabilization via permutational premelting

“…Theoretical studies of the finite temperature behavior of clusters of the latter class have been almost solely dedicated to alkali halide systems. [12][13][14][15][16][17][18] Such clusters with over ∼60 ions tend to display extended periods in either ordered or disordered phases, with only occasional jumps in between, 12,16,17 whereas simulations of smaller clusters have revealed a variety of dynamic phase coexistence states 13,15,18 during premelting, where various isomers are sampled. Such works, and other studies on small metal clusters, 19,20 have been instrumental in providing uniquely detailed insights into cluster melting.…”