Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-10T12:18:02.132Z Has data issue: false hasContentIssue false
  • English
  • Français

About activation energy of viscous flow of glasses and melts

Published online by Cambridge University Press:  09 February 2015

Michael I. Ojovan
Michael I. Ojovan*
Affiliation:
Department of Materials, Imperial College London, London SW7 2AZ, UK
Get access

Abstract

Data on a viscous flow model based on network defects – broken bonds termed configurons – were analysed. An universal equation has been derived for the variable activation energy of viscous flow Q(T) of the generic Frenkel equation of viscosity η(T)=A∙exp(Q/RT) which is known to have two constant asymptotes – high QH at low temperatures and low QL at high temperatures. The defect model of flow used by e.g. Doremus, Mott, Nemilov, Sanditov states that higher the concentration of defects (e.g. configurons) the lower the viscosity. We have used the configuron percolation theory (CPT) which treats glass–liquid transition as a percolation-type phase transition. Additionally the CPT results in a continuous temperature relationship for viscosity valid for both glassy and liquid amorphous materials. We show that a particular result of CPT is the universal temperature relationship for the activation energy of viscous flow: Q(T)=QL+RT∙ln[1+exp(-Sd/R) exp((QH-QL)/RT)] which depends on asymptotic energies QL (for the liquid phase) and QH (for the glassy phase), and on entropy of configurons Sd. This equation has two asymptotes, namely Q(T<<Tg) = QH, and Q(T>>Tg) = QL. Moreover we demonstrate that the equation for Q(T) practically coincides in the transition range of temperatures with known Sanditov equation.

Keywords

amorphousliquiddefects
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1757: Symposium UU – Structure-Property Relations in Amorphous Solids , 2015 , mrsf14-1757-uu01-10
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Sanditov, D.S.. J. Non-Cryst. Solids, 400, 12–20 (2014).CrossRefGoogle Scholar
Sanditov, D.S.. J. Non-Cryst. Solids, 385, 148 (2014).CrossRefGoogle Scholar
Ojovan, M.I.. J. Non-Cryst. Solids 382, 79 (2013).CrossRefGoogle Scholar
Stanzione, J.F. III, Strawhecker, K.E., Wool, R.P.. J. Non-Cryst. Solids 357, 311 (2011).CrossRefGoogle Scholar
Ma, D., Stoica, A.D., Wang, X.-L.. Nature Materials, 8, 30 (2009).CrossRefGoogle Scholar
Louzguine-Luzgin, D.V., Belosludov, R., Yavari, A.R., Georgarakis, K., Vaughan, G., Kawazoe, Y., Egami, T., Inoue, A.. J. Appl. Phys., 110, 043519 (2011).CrossRefGoogle Scholar
Louzguine-Luzgin, D.V.. Journal of Alloys and Compounds, 586, S2–S8 (2014).CrossRefGoogle Scholar
Ojovan, M.I.. Entropy, 10, 334–364 (2008).CrossRefGoogle Scholar
Martinez, L.-M., Angell, C.A.. Nature, 410, 663–667 (2001).CrossRefGoogle Scholar
Ojovan, M.I., Lee, W.E.. J. Non-Cryst. Solids, 356, 2534 (2010).CrossRefGoogle Scholar
Ojovan, M.. Phys. Chem. Glasses, 53, 143 (2012).Google Scholar
Avramov, I.. J. Non-Cryst. Solids 357, 391 (2011).CrossRefGoogle Scholar
Fluegel, A.. Glass Technol., 48, 13 (2007).Google Scholar
Volf, M.B.. Mathematical approach to glass. Elsevier, Amsterdam ( 1988).Google Scholar
Angell, C.A.. MRS Bulletin, 33, 544 (2008).CrossRefGoogle Scholar
Angel, C.A.. J. Phys. Chem. Solids, 49, 863 (1988).CrossRefGoogle Scholar
Doremus, R.H.. J. Appl. Physics, 92, 7619 (2002).CrossRefGoogle Scholar
Möbus, G., Ojovan, M., Cook, S. et.al, J. Nucl. Mater., 396, 264 (2010).CrossRefGoogle Scholar
Qin, Q., McKenna, G.B.. J. Non-Cryst. Solids 352, 2977 (2006).CrossRefGoogle Scholar
Nemilov, S.V.. J. Non-Cryst. Solids 353, 4613 (2007).CrossRefGoogle Scholar
Douglas, R.W.. J. Soc. Glass Technology, 33, 138 (1949).Google Scholar
Ozhovan, M.I.. J. Exp. Theor. Phys., 103(5) 819–829 (2006).CrossRefGoogle Scholar
Ojovan, M.I., Travis, K.P., Hand, R.J.. J. Phys.: Condensed Matter, 19, 415107 (2007).Google Scholar
Ojovan, M.I.. Int. J. Applied Glass Science, 5, (1) 22–25 (2014).CrossRefGoogle Scholar
Sanditov, D.S.. J. Exp. Theor. Phys., 110(4) 675–688 (2010).CrossRefGoogle Scholar
Chechetkina, E.A.. J. Non-Cryst. Solids, 201, 146 (1996).CrossRefGoogle Scholar