Interatomic Potential in the Nonequilibrium Warm Dense Matter Regime

Z. Chen, M. Mo, L. Soulard, V. Recoules, P. Hering, Y. Y. Tsui, S. H. Glenzer, and A. Ng

Phys. Rev. Lett. 121, 075002 – Published 15 August 2018

Abstract

We present a new measurement of lattice disassembly times in femtosecond-laser-heated polycrystalline Au nanofoils. The results are compared with molecular dynamics simulations incorporating a highly optimized, embedded-atom-method interatomic potential. For absorbed energy densities of $0.9 - 4.3 MJ / kg$ , the agreement between the experiment and simulation reveals a single-crystal-like behavior of homogeneous melting and corroborates the applicability of the interatomic potential in the nonequilibrium warm dense matter regime. For energy densities below $0.9 MJ / kg$ , the measurement is consistent with nanocrystal behavior where melting is initiated at the grain boundaries.

Received 3 August 2017
Revised 4 June 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.075002

Physics Subject Headings (PhySH)

High-energy-density plasmas Interatomic & molecular potentials

Warm-dense matter

Molecular dynamics

Plasma Physics

Authors & Affiliations

Z. Chen¹, M. Mo¹, L. Soulard², V. Recoules², P. Hering¹, Y. Y. Tsui³, S. H. Glenzer^1,*, and A. Ng^4,†

¹SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
²CEA, DAM, DIF, 91297 Arpajon, France
³Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G-2V4, Canada
⁴Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T-1Z1, Canada