skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Ion-beam-induced planarization, densification, and exfoliation of low-density nanoporous silica

Authors:
 [1]; ORCiD logo [1]
  1. Lawrence Livermore National Laboratory, Livermore, California 94550, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1394675
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 111; Journal Issue: 13; Related Information: CHORUS Timestamp: 2018-02-15 01:11:09; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Kucheyev, S. O., and Shin, S. J.. Ion-beam-induced planarization, densification, and exfoliation of low-density nanoporous silica. United States: N. p., 2017. Web. doi:10.1063/1.4998193.
Kucheyev, S. O., & Shin, S. J.. Ion-beam-induced planarization, densification, and exfoliation of low-density nanoporous silica. United States. doi:10.1063/1.4998193.
Kucheyev, S. O., and Shin, S. J.. 2017. "Ion-beam-induced planarization, densification, and exfoliation of low-density nanoporous silica". United States. doi:10.1063/1.4998193.
@article{osti_1394675,
title = {Ion-beam-induced planarization, densification, and exfoliation of low-density nanoporous silica},
author = {Kucheyev, S. O. and Shin, S. J.},
abstractNote = {},
doi = {10.1063/1.4998193},
journal = {Applied Physics Letters},
number = 13,
volume = 111,
place = {United States},
year = 2017,
month = 9
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 25, 2018
Publisher's Accepted Manuscript

Save / Share:
  • Numerical simulations on UV-laser-induced densification of fused silica have been performed using classical molecular dynamics. The effect of laser irradiation is modeled by the energy transfer from the absorbed laser photons to the bonded silicon and oxygen atoms, i.e., the thermal effects of laser-irradiation on silica glass. Results from simulations at various laser pulse duration, pressure, and temperature conditions show that longer laser pulse duration, higher pressure, and higher temperature cause larger densification. We have also compared the microstructural and elastic properties of fused silica desndified by UV-laser and hydrostatic pressure, respectively. Similar change sare observed in both cases; severalmore » notable differences are noticed, too, and include Si-O bond length change, number of over-coordinated atoms, and ring distributions.« less
  • Classical molecular dynamics simulations have been performed to study the UV-laser-induced densification in fused silica. Relationships between induced densification and absorbed laser fluence under different laser durations are established. We have also studied the effects of laser irradiation on the radial distribution functions, static structure factor, bond-angle distributions, ring-size distribution, and elastic constants of fused silica.
  • We investigate the physical mechanisms responsible for waveguide formation in silica glass induced by 1 kHz intense femtosecond laser pulses from a Ti-sapphire laser at 0.8 {mu}m as well as from a femtosecond optical parametric amplifier at 1.5 {mu}m. It is demonstrated that the densification taking place at the irradiated region is the principal cause for refractive index change in the waveguides written with both 0.8 and 1.5 {mu}m pulses. The birefringence induced by the stress arising from such densification and its behavior against thermal annealing are also studied.
  • The authors studied the anomalous behaviors of vitreous silica under the combined influence of high temperature and pressure, by using molecular dynamics simulations based on a charge-transfer three-body potential. Accordingly, anomalous properties, such as the minimum in the bulk modulus at {approx}2-3 GPa and the negative thermal expansion while under pressure, are inherently connected to the ability of the glass to undergo irreversible densification. Their simulations reveal the structural features responsible for this behavior, as well as the extent to which these properties can be tailored through specific processing routes and hence create glass that is less susceptible to radiationmore » damage.« less
  • A neutron scattering technique was developed to measure the density of heavy water confined in a nanoporous silica matrix in a temperature-pressure range, from 300 to 130 K and from 1 to 2,900 bars, where bulk water will crystalize. We observed a prominent hysteresis phenomenon in the measured density profiles between warming and cooling scans above 1,000 bars. We inter- pret this hysteresis phenomenon as support (although not a proof) of the hypothetical existence of a first-order liquid liquid phase transition of water that would exist in the macroscopic system if crystallization could be avoided in the relevant phase region.more » Moreover, the density data we obtained for the confined heavy water under these conditions are valuable to large communities in biology and earth and planetary sciences interested in phenomena in which nanometer-sized water layers are involved.« less