Modified Angell Plot of Viscous Flow with Application to Silicate and Metallic Glass‐Forming Liquids

Abstract

The behavior of the Vogel-Fulcher-Tammann (VFT), Avramov and Milchev (AM) and Mauro, Yue, Ellison, Gupta and Allan (MYEGA) functions of viscous flow in relation to t = T g /(TÀT o ) is analyzed, where T g is glass transition temperature and T o is the temperature in the VFT equation at which the configurational entropy becomes zero. The T g -scaled Arrhenius plot (the Angell plot) has been modified. The log gÀ(T g /T) relationships in the Angell plot were modified as log g-(T g )/(TÀT o ) relationships (T g -scaled VFT plot). The values of parameter m 1 = d(log g)/dt│ T=Tg for some silicate and metallic glass-forming liquids are presented too. The parameter m 1 still exhibits "fragility" effect as does the kinetic fragility parameter m = d(log g)/d (T g /T)│ T=Tg in the Angell plot. The plot of log g VFT in relation to t = T g /(TÀT o ) is the linear function unlike the Angell plot. The dependences of log g MYEGA and log g AM on t are not linear. It is possible to present the dependences of log g as functions of m 1 and t in the form of 3D graphs. *analeto@yahoo.com

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