Structure and stability of finite gold nanowires

TL;DR

This study uses molecular dynamics simulations to analyze the structure, vibrational properties, and stability of finite gold nanowires with face-centered cubic structures, revealing multi-walled formations and vibrational instabilities.

Contribution

It provides new insights into the formation, stability, and vibrational characteristics of gold nanowires, including the emergence of multi-walled structures and vibrational mode analysis.

Findings

Some nanowires form stable multi-walled cylindrical structures.

A few percent of vibrational modes are unstable due to incomplete restructuring.

Vibrational properties are affected by the nanowires' initial structure and annealing process.

Abstract

Finite gold nanowires containing less than 1000 atoms are studied using the molecular dynamics simulation method and embedded atom potential. Nanowires with the face-centered cubic structure and the (111) oriented cross-section are prepared at T=0 K. After annealing and quenching the structure and vibrational properties of nanowires are studied at room temperature. Several of these nanowires form multi-walled structures of lasting stability. They consist of concentrical cylindrical sheets and resemble multi-walled carbon nanotubes. Vibrations are investigated by diagonalization of the dynamical matrix. It was found that several percents of vibrational modes are unstable because of uncompleted restructuring of initial fcc nanowires.