# Lowering of surface melting temperature in atomic clusters with a nearly closed shell structure

## TL;DR

This study explores how nearly closed shell atomic clusters with extra atoms exhibit reduced surface melting temperatures due to structural stress, potentially explaining experimental observations of suppressed surface melting.

## Contribution

It introduces a mechanism linking structural stress in nearly closed shell clusters to lowered surface melting temperatures, supported by Monte Carlo simulations.

## Key findings

- Strained clusters have lower energy barriers for surface diffusion.
- Surface melting temperature T_S can fall below bulk values.
- The mechanism explains experimental suppression of surface melting.

## Abstract

We investigate the interplay of particle number, N, and structural properties of selected clusters with N=12 up to N=562 by employing Gupta potentials parameterized for Aluminum and extensive Monte-Carlo simulations. Our analysis focuses on closed shell structures with extra atoms. The latter can put the cluster under a significant stress and we argue that typically such a strained system exhibits a reduced energy barrier for (surface) diffusion of cluster atoms. Consequently, also its surface melting temperature, T_S, is reduced, so that T_S separates from and actually falls well below the bulk value. The proposed mechanism may be responsible for the suppression of the surface melting temperature observed in a recent experiments.