Activation Entropy as a Key Factor Controlling the Memory Effect in Glasses.
Phys Rev Lett
; 125(13): 135501, 2020 Sep 25.
Article
en En
| MEDLINE
| ID: mdl-33034495
ABSTRACT
As opposed to the common monotonic relaxation process of glasses, the Kovacs memory effect describes an isothermal annealing experiment, in which the enthalpy and volume of a preannealed glass first increases before finally decreasing toward equilibrium. This interesting behavior has been observed for many materials and is generally explained in terms of heterogeneous dynamics. In this Letter, the memory effect in a model Au-based metallic glass is studied using a high-precision high-rate calorimeter. The activation entropy (S^{*}) during isothermal annealing is determined according to the absolute reaction rate theory. We observe that the memory effect appears only when the second-annealing process has a large S^{*}. These results indicate that a large value of S^{*} is a key requirement for observation of the memory effect and this may provide a useful perspective for understanding the memory effect in both thermal and athermal systems.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Phys Rev Lett
Año:
2020
Tipo del documento:
Article
País de afiliación:
China