Computational study of quasi-2d liquid state in free standing platinum, silver, gold, and copper monolayers

Li Ming Yang, Ariel B. Ganz, Matthew Dornfeld, Eric Ganz

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Recently, freestanding atomically thick Fe metal patches up to 10 atoms wide have been fabricated experimentally in tiny pores in graphene. This concept can be extended conceptually to extended freestanding monolayers. We have therefore performed ab initio molecular dynamics simulations to evaluate the early melting stages of platinum, silver, gold, and copper freestanding metal monolayers. Our calculations show that all four freestanding monolayers will form quasi-2D liquid layers with significant out-of-plane motion and diffusion in the plane. Remarkably, we observe a 4% reduction in the Pt most likely bond length as the system enters the liquid state at 2400 K (and a lower effective spring constant), compared to the system at 1200 and 1800 K. We attribute this to the reduced average number of bonds per atom in the Pt liquid state. We used the highly accurate and reliable Density Functional Theory (DFT-D) method that includes dispersion corrections. These liquid states are found at temperatures of 2400 K, 1050 K, 1600 K, and 1400 K for platinum, silver, gold, and copper respectively. The pair correlation function drops in the liquid state, while the bond orientation order parameter is reduced to a lesser degree. Movies of the simulations can be viewed online (see Supplementary Material).

Original languageEnglish (US)
Article number1
Pages (from-to)1-13
Number of pages13
JournalCondensed Matter
Volume1
Issue number1
DOIs
StatePublished - Dec 2016

Bibliographical note

Funding Information:
Acknowledgments: We thank the Minnesota Supercomputing Institute (MSI) at the University of Minnesota for providing supercomputing resources. The molecular dynamics simulations were carried out on the Mesabi supercomputer at the MSI. L.M.Y. acknowledges support from startup funding from Huazhong University of Science and Technology. Research reported in this publication was supported by the National Institutes of Health under award T32-DK007158 (A.G.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) or the National Institutes of Health.

Publisher Copyright:
© 2016 by the authors; licensee MDPI, Basel, Switzerland.

Keywords

  • 2-D liquid
  • 2-D melting
  • Density functional theory
  • Molecular dynamics

Fingerprint

Dive into the research topics of 'Computational study of quasi-2d liquid state in free standing platinum, silver, gold, and copper monolayers'. Together they form a unique fingerprint.

Cite this