کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1485125 | 1510533 | 2007 | 8 صفحه PDF | دانلود رایگان |

Published dielectric and shear data of six molecular glass formers and one polymer are evaluated in terms of a spectrum of thermally activated processes, with the same barrier density for the retardation spectrum of shear and dielectrics. The viscosity, an independent parameter of the fit, seems to be related to the high-barrier cutoff time of the dielectric signal, in accordance with the idea of a renewal of the relaxing entities after this critical time. In the five cases where one can fit accurately, the temperature dependence of the high-barrier cutoff follows the shoving model. The Johari–Goldstein peaks, seen in four of our seven cases, are describable in terms of gaussians in the barrier density, superimposed on the high-frequency tail of the α-process. Dielectric and shear measurements of the same substance find the same peak positions and widths of these gaussians, but in general a different weight.
Journal: Journal of Non-Crystalline Solids - Volume 353, Issues 41–43, 1 November 2007, Pages 3812–3819