Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids

Ting Wang, Ozgur Gulbiten, Rongping Wang, Zhiyong Yang, Anita Smith, Barry Luther-Davies, Pierre Lucas

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The structural relaxation properties of 34 compositions of Ge-As-Se glass forming liquids are investigated by differential scanning calorimetry (DSC). The fragility index (m) and activation energies for enthalpy relaxation (E a) exhibit universal trends with respect to stoichiometry and mean coordination (〈r〉), respectively. The liquid fragility which defines the full temperature dependence of the relaxation processes shows no well defined trend with respect to 〈r〉 but instead is found to be closely determined by the excess or deficiency in selenium with respect to stoichiometry. The mean coordination on the other hand appears to be an accurate predictor of the activation energy near the glass transition where most constraints are still intact. No intermediate phase is observed in either case. These results emphasize that chemical effects rather than topological effects appear to control the wide ranging structural mobility of these glass forming liquids. The consequences of these findings in terms of the thermal stability of the corresponding glasses are discussed. It is similarly found that sub-T g relaxation is controlled by stoichiometry rather than topology.

Original languageEnglish (US)
Pages (from-to)1436-1442
Number of pages7
JournalJournal of Physical Chemistry B
Volume118
Issue number5
DOIs
StatePublished - Feb 6 2014

Fingerprint

Stoichiometry
stoichiometry
Glass
glass
Liquids
liquids
Activation energy
Structural relaxation
Selenium
Relaxation processes
activation energy
trends
chemical effects
Glass transition
Differential scanning calorimetry
Enthalpy
Thermodynamic stability
selenium
Topology
thermal stability

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Materials Chemistry
  • Surfaces, Coatings and Films

Cite this

Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids. / Wang, Ting; Gulbiten, Ozgur; Wang, Rongping; Yang, Zhiyong; Smith, Anita; Luther-Davies, Barry; Lucas, Pierre.

In: Journal of Physical Chemistry B, Vol. 118, No. 5, 06.02.2014, p. 1436-1442.

Research output: Contribution to journalArticle

Wang, Ting ; Gulbiten, Ozgur ; Wang, Rongping ; Yang, Zhiyong ; Smith, Anita ; Luther-Davies, Barry ; Lucas, Pierre. / Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids. In: Journal of Physical Chemistry B. 2014 ; Vol. 118, No. 5. pp. 1436-1442.
@article{4facfc1fc7a24268b747d08503f5e7db,
title = "Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids",
abstract = "The structural relaxation properties of 34 compositions of Ge-As-Se glass forming liquids are investigated by differential scanning calorimetry (DSC). The fragility index (m) and activation energies for enthalpy relaxation (E a) exhibit universal trends with respect to stoichiometry and mean coordination (〈r〉), respectively. The liquid fragility which defines the full temperature dependence of the relaxation processes shows no well defined trend with respect to 〈r〉 but instead is found to be closely determined by the excess or deficiency in selenium with respect to stoichiometry. The mean coordination on the other hand appears to be an accurate predictor of the activation energy near the glass transition where most constraints are still intact. No intermediate phase is observed in either case. These results emphasize that chemical effects rather than topological effects appear to control the wide ranging structural mobility of these glass forming liquids. The consequences of these findings in terms of the thermal stability of the corresponding glasses are discussed. It is similarly found that sub-T g relaxation is controlled by stoichiometry rather than topology.",
author = "Ting Wang and Ozgur Gulbiten and Rongping Wang and Zhiyong Yang and Anita Smith and Barry Luther-Davies and Pierre Lucas",
year = "2014",
month = "2",
day = "6",
doi = "10.1021/jp412226w",
language = "English (US)",
volume = "118",
pages = "1436--1442",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "5",

}

TY - JOUR

T1 - Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids

AU - Wang, Ting

AU - Gulbiten, Ozgur

AU - Wang, Rongping

AU - Yang, Zhiyong

AU - Smith, Anita

AU - Luther-Davies, Barry

AU - Lucas, Pierre

PY - 2014/2/6

Y1 - 2014/2/6

N2 - The structural relaxation properties of 34 compositions of Ge-As-Se glass forming liquids are investigated by differential scanning calorimetry (DSC). The fragility index (m) and activation energies for enthalpy relaxation (E a) exhibit universal trends with respect to stoichiometry and mean coordination (〈r〉), respectively. The liquid fragility which defines the full temperature dependence of the relaxation processes shows no well defined trend with respect to 〈r〉 but instead is found to be closely determined by the excess or deficiency in selenium with respect to stoichiometry. The mean coordination on the other hand appears to be an accurate predictor of the activation energy near the glass transition where most constraints are still intact. No intermediate phase is observed in either case. These results emphasize that chemical effects rather than topological effects appear to control the wide ranging structural mobility of these glass forming liquids. The consequences of these findings in terms of the thermal stability of the corresponding glasses are discussed. It is similarly found that sub-T g relaxation is controlled by stoichiometry rather than topology.

AB - The structural relaxation properties of 34 compositions of Ge-As-Se glass forming liquids are investigated by differential scanning calorimetry (DSC). The fragility index (m) and activation energies for enthalpy relaxation (E a) exhibit universal trends with respect to stoichiometry and mean coordination (〈r〉), respectively. The liquid fragility which defines the full temperature dependence of the relaxation processes shows no well defined trend with respect to 〈r〉 but instead is found to be closely determined by the excess or deficiency in selenium with respect to stoichiometry. The mean coordination on the other hand appears to be an accurate predictor of the activation energy near the glass transition where most constraints are still intact. No intermediate phase is observed in either case. These results emphasize that chemical effects rather than topological effects appear to control the wide ranging structural mobility of these glass forming liquids. The consequences of these findings in terms of the thermal stability of the corresponding glasses are discussed. It is similarly found that sub-T g relaxation is controlled by stoichiometry rather than topology.

UR - http://www.scopus.com/inward/record.url?scp=84893864577&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84893864577&partnerID=8YFLogxK

U2 - 10.1021/jp412226w

DO - 10.1021/jp412226w

M3 - Article

AN - SCOPUS:84893864577

VL - 118

SP - 1436

EP - 1442

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 5

ER -