LAUSR

Abstract This work addresses the study by thermostimulated depolarization currents (TSDC) of Johari-Goldstein (JG) β-relaxations in glass forming systems. Here we analyze the differences between the β-relaxation and the fast secondary (γ, δ, e, …) relaxations on the one hand, and the α-relaxation on the other. It is shown that TSDC is able to characterize JG although this mobility is often close to, or even partially overlapped with, the α-relaxation. It is also shown that the Starkweather line or zero entropy line (ZEL) can be used as a reference element to identify the secondary relaxations: non-compliance with the ZEL is an indicator of cooperativity. We finally showed that the non-cooperativeness of the Johari-Goldstein relaxation is highlighted by the joint consideration of the Coupling Model and the Starkweather line.