Vogel-Fulcher behavior

On the other hand, polymeric materials show universal aspects of glass transition behavior, just like other materials. For instance, the classical Vogel-Fulcher behavior... 

Given the broad distribution of r s in rls, it is not surprising that the temperature dependence of the relaxation time corresponding to Tm is found to be non-Arrhenius. This is clearly shown for pmn in Figure 15.9, which gives results at 1 bar and 4-8 kbar. The departure from Arrhenius behavior can be generally satisfactorily described in a variety of ways many of which can be expressed [14,28] in the form of the Vogel-Fulcher (V-F) equation... 

E0 and the infinite temperature relaxation time To are independent of temperature, and (ii) in the isotropic phase near the I-N transition, the temperature dependence of ts2(T) shows marked deviation from Arrhenius behavior and can be well-described by the Vogel-Fulcher-Tammann (VFT) equation ts2(T) = TyFrQxp[B/(T — TVFF), where tvff, B, and tvft are constants, independent of temperature. Again these features bear remarkable similarity with... 

In the high-temperature range, both relaxation modes exhibit Vogel-Fulcher-Tammann-Hesse (VFTH) behavior ... 

It is remarkable that the free-volume-based Doolittle equation devised to explain the temperature dependence of the viscosity of a generic simple atomic liquid can account so well both for the viscous behavior of metallic glass alloys through the Vogel, Fulcher, and Tammann (VFT) equation representation discussed in Chapter 1 and for the behavior of the much more complex sub-cooled... 

Vogel-Fulcher-Tammann behavior they found that the temperature dependence of the relaxation for both could be described by the following relationship [40] ... 

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