### Abstract

We discuss how concepts from rigidity percolation can be used to understand the low frequency excitations and elastic properties of network glasses like Ge_{x}As_{y}Se_{1-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 Ge_{x}se_{1-x} glasses. The floppy modes, observed in inelastic neutron scattering, disappear as 〈r〉 increases from 2 up to around 2.4.

Original language | English (US) |
---|---|

Pages (from-to) | 19-24 |

Number of pages | 6 |

Journal | Journal of Non-Crystalline Solids |

Volume | 114 |

Issue number | PART 1 |

DOIs | |

State | Published - Dec 1 1989 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Ceramics and Composites
- Electronic, Optical and Magnetic Materials

### Cite this

*Journal of Non-Crystalline Solids*,

*114*(PART 1), 19-24. https://doi.org/10.1016/0022-3093(89)90056-2

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

Research output: Contribution to journal › Article

*Journal of Non-Crystalline Solids*, vol. 114, no. PART 1, pp. 19-24. https://doi.org/10.1016/0022-3093(89)90056-2

}

TY - JOUR

T1 - Mechanical and vibrational properties of network structures

AU - Thorpe, Michael

AU - Cai, Y.

PY - 1989/12/1

Y1 - 1989/12/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=0024780342&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024780342&partnerID=8YFLogxK

U2 - 10.1016/0022-3093(89)90056-2

DO - 10.1016/0022-3093(89)90056-2

M3 - Article

AN - SCOPUS:0024780342

VL - 114

SP - 19

EP - 24

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

IS - PART 1

ER -