Asymmetric double-well potentials ADWP

At temperatures say, below 70 K further relaxation processes occur. There, the frequency dependence of "(v) changes from a negative slope to a positive one. In this temperature range, thermally activated dynamics in asymmetric double-well potentials (ADWP) and, below 10 K, tunneling phenomena were discussed relating to the so-called low-temperature anomalies of glasses.27,30,31... 

Figure 7.07. Schematic illustration of an NSR process due to a transition 1- 2 in an asymmetric double-well potential (ADWP) characterizing the local low-energy configurations in glassy solids (after Kanert et al., 1994).

In early interpretations, static distributions of asymmetric double-well potentials (ADWP) were assumed to exist for the locally mobile ions, providing a wide range of relaxation times. This model, which was based on ideas of PoUak and Pike [32], has often been used to fit experimental data [33, 34]. 

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