Non-exponential relaxation in disordered materials : Phenomenological correlations and spectrally selective experiments

摘要: Abstract In most glass-forming materials external perturbations are relaxed in a non-exponential fashion. It is shown that the degree of non-exponentiality phenomenologically correlated with departure from simple thermally activated behavior as measured by fragility index m. model glass formers such Ge-As-Se ternary alloy, and to some for amorphous general, correlations these properties observed also other characteristic features. These include specific heat step aging kinetics transformation range. While phenomenological have proven very useful rationalizing many formers, they provided little direct insight into nature relaxation itself. this respect invention spectrally selective techniques, allowing manipulate observable primary response, has yielded evidence its heterogeneous character. As an example developments i...