Eur. Phys. J. E (2014) 37: 52
https://doi.org/10.1140/epje/i2014-14052-y

Regular Article

Calorimetric determination of fragility in glass forming liquids: T_f vs. T_g-onset methods

State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, 066004, Hebei, China

^* e-mail: Limin_Wang@ysu.edu.cn

Received: 24 January 2014
Revised: 29 May 2014
Accepted: 12 June 2014
Published online: 26 June 2014

Abstract

The calorimetric determination of the fragility m-index is compared using the T _f and T _g-onset methods for typical metallic and molecular glass forming systems of Pd₃₉Ni₁₀Cu₃₀P₂₁, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T _f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T _g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T _f method produces less uncertainty.