The long-wavelength limit of the structure factor of amorphous silicon and vitreous silica

Adam M R De Graff, Michael Thorpe

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Liquids are in thermal equilibrium and have a non-zero structure factor = = in the long-wavelength limit where is the number density, is the temperature, is the scattering vector and is the isothermal compressibility. The first part of this result involving the number (or density) fluctuations is a purely geometrical result and does not involve any assumptions about thermal equilibrium or ergodicity, so is obeyed by all materials. From a large computer model of amorphous silicon, local number fluctuations extrapolate to give = 0.035 0.001. The same computation on a large model of vitreous silica using only the silicon atoms and rescaling the distances gives = , which suggests that this numerical result is robust and perhaps similar for all amorphous tetrahedral networks. For vitreous silica, it is found that = , close to the experimental value of = obtained recently by small-angle neutron scattering. Further experimental and modeling studies are needed to determine the relationship between the fictive temperature and structure.

Original languageEnglish (US)
Pages (from-to)22-31
Number of pages10
JournalActa Crystallographica Section A: Foundations of Crystallography
Volume66
Issue number1
DOIs
StatePublished - 2010

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Silicon
Fused silica
Amorphous silicon
Silicon Dioxide
amorphous silicon
Hot Temperature
Small Angle Scattering
silicon dioxide
Wavelength
Temperature
Neutrons
Neutron scattering
Compressibility
wavelengths
Computer Simulation
compressibility
neutron scattering
Scattering
Atoms
temperature

Keywords

  • Amorphous silicon
  • Computer model
  • Density fluctuations
  • Long-wavelength
  • Neutron scattering
  • Silicon dioxide
  • Structure factor
  • Vitreous silica
  • X-ray scattering

ASJC Scopus subject areas

  • Structural Biology

Cite this

The long-wavelength limit of the structure factor of amorphous silicon and vitreous silica. / De Graff, Adam M R; Thorpe, Michael.

In: Acta Crystallographica Section A: Foundations of Crystallography, Vol. 66, No. 1, 2010, p. 22-31.

Research output: Contribution to journalArticle

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