Mechanical and vibrational properties of network structures

Michael Thorpe, Y. Cai

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We discuss how concepts from rigidity percolation can be used to understand the low frequency excitations and elastic properties of network glasses like GexAsySe1-x-t-y. When the mean coordination 〈r〉 = 2 + 2x + y is low, these materials are soft and their properties are strongly influenced by low frequency phonons. We use a bond depleted diamond lattice to mimic the coordination properties of the glass. We show that a model with only covalent forces is unstable for 〈rm〉 < 2.4, but can be stabilized by small additional forces. We calculate the elastic constants and the density of states as a function of 〈r〉. Despite the simplicity of the model, the rounded phase transition at 〈r> = 2.4 is consistent with recent experimental results involving ultrasonics and inelastic neutron scattering on Gexse1-x glasses. The floppy modes, observed in inelastic neutron scattering, disappear as 〈r〉 increases from 2 up to around 2.4.

Original languageEnglish (US)
Pages (from-to)19-24
Number of pages6
JournalJournal of Non-Crystalline Solids
Volume114
Issue numberPART 1
DOIs
StatePublished - Dec 1 1989
Externally publishedYes

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Inelastic neutron scattering
mechanical properties
Glass
glass
inelastic scattering
neutron scattering
low frequencies
Diamond
Phonons
rigidity
Rigidity
Diamonds
phonons
elastic properties
ultrasonics
Ultrasonics
diamonds
excitation

ASJC Scopus subject areas

  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials

Cite this

Mechanical and vibrational properties of network structures. / Thorpe, Michael; Cai, Y.

In: Journal of Non-Crystalline Solids, Vol. 114, No. PART 1, 01.12.1989, p. 19-24.

Research output: Contribution to journalArticle

Thorpe, Michael ; Cai, Y. / Mechanical and vibrational properties of network structures. In: Journal of Non-Crystalline Solids. 1989 ; Vol. 114, No. PART 1. pp. 19-24.
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