Finite temperature properties for zinc nanoclusters

Abstract

The Gupta-type many-body potential was applied to describe the interactions between atoms in zinc nanoclusters. From the calculated ground state structures, obtained by Brownian-type molecular dynamic simulation, we investigated the temperature effect of zinc clusters. We studied in particular the constant volume specific heat CV which is a thermodynamic quantity and also the relative bond length Lindemann parameter δ which is a geometric quantity. Effort is devoted to revealing the anomalies observed in these quantities for Zn clusters and making a comparison with those of the typical sp-type metallic clusters. To this end, we have chosen to calculate the CV and δ of clusters Znn for 29, 33, and 53 which are judged to be less stable by the energy difference and the second energy difference as well as 6, 36, 42, and 49 which are judged by the same energy criteria to be relatively more stable. Our results of simulation show that the structures of CV and δ exhibit unusual phase transition behaviors which are drastically different from those of the usual metallic clusters. General scenarios observed in the simulation are the prevalence of the pre-melting phenomenon predicted in all of the clusters studied here.