Chapter 52. Molecular-Dynamics Simulations of Structural Transformation and Dynamical Correlations in Silica Glass at High Pressures

  1. John B. Wachtman Jr.
  1. Wei Jin

Published Online: 26 MAR 2008

DOI: 10.1002/9780470314784.ch52

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 16, Issue 5

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 16, Issue 5

How to Cite

Jin, W. (1995) Molecular-Dynamics Simulations of Structural Transformation and Dynamical Correlations in Silica Glass at High Pressures, in Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 16, Issue 5 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314784.ch52

Author Information

  1. Levich Institute, TIM, City College of New York, New York, NY 10031

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1995

ISBN Information

Print ISBN: 9780470375389

Online ISBN: 9780470314784

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Keywords:

  • glazing;
  • radiating;
  • laminated;
  • proportional;
  • orientation

Summary

Structural transformations and intermediate-range order (IRO) in SiO2 glass at high pressures are studied with the molecular-dynamics (MD) approach. The MD simulations cover a wide range of mass densities — from normal density (2.20 g/cm3) to the density corresponding to stishovite (4.28 g/cm3). At twice the normal density, the height of the first sharp diffraction peak (FSDP) in the static structure factor S(q) is considerably diminished and its position changes from 1.6 to 2.2 Å−1. Concomitantly, a new peak appears around 3.2 Å−1. As the density increases from 2.20 to 4.28 g/cm3, the Si-O bond length increases from 1.61 to 1.67 Å, the Si-O and O-O coordinations change from 4 to 5.8 and from 6 to 12, respectively, and the O-Si-O bond-angle changes from 109° to 90°. Combined with the results for ring distributions, dynamic structural factors, phonon density of states, and participation ratios, there is a clear evidence that the tetrahedral network at normal density transforms into a network of Si(O1/3)6 octahedra jointed at corners and edges.