skip to main content

Title: Molecular dynamics simulation of Coulomb explosion, melting and shock wave creation in silicon after an ionization pulse

Strong electronic stopping power of swift ions in a semiconducting or insulating substrate can lead to localized electron stripping. The subsequent repulsive interactions among charged target atoms can cause Coulomb explosion. Using molecular dynamics simulation, we simulate Coulomb explosion in silicon by introducing an ionization pulse lasting for different periods, and at different substrate temperatures. We find that the longer the pulse period, the larger the melting radius. The observation can be explained by a critical energy density model assuming that melting required thermal energy density is a constant value and the total thermal energy gained from Coulomb explosion is linearly proportional to the ionization period. Our studies also show that melting radius is larger at higher substrate temperatures. The temperature effect is explained due to a longer structural relaxation above the melting temperature at original ionization boundary due to lower heat dissipation rates. Furthermore, simulations show the formation of shock waves, created due to the compression from the melting core.
Authors:
;  [1] ;  [2] ;  [3]
  1. Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 (China)
  2. Department of Nuclear Engineering, Texas A and M University, College Station, Texas 77843 (United States)
  3. Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States)
Publication Date:
OSTI Identifier:
22273634
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 14; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPUTERIZED SIMULATION; COULOMB EXCITATION; ELECTRONS; ENERGY DENSITY; ENERGY LOSSES; MELTING; MELTING POINTS; MOLECULAR DYNAMICS METHOD; RELAXATION; SHOCK WAVES; SILICON; STOPPING POWER; STRIPPING; SUBSTRATES; THERMAL DIFFUSIVITY; THERMAL EFFLUENTS