Artículo
Determining the heterogeneity in time of the dynamics within a slowly relaxing region of a supercooled liquid: Role of sharp relaxation events
Alarcon, Laureano Martin
; Frechero, Marisa Alejandra
; Montani, Ruben Alfredo; Appignanesi, Gustavo Adrian
Fecha de publicación:
26/08/2009
Editorial:
American Physical Society
Revista:
Physical Review E: Statistical, Nonlinear and Soft Matter Physics
ISSN:
1539-3755
e-ISSN:
1550-2376
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Supercooled liquids have been shown to be dynamically heterogeneous with different regions of the system presenting dynamics that vary from each other even by orders of magnitude. Computer simulations have confirmed such a picture by detecting that the mobile particles in model glass formers are not homogeneously distributed within the system but arranged in clusters. More recently, the dynamics of small systems has been characterized by demonstrating that their structural relaxation is not homogeneous in time, in the sense that it does not evolve gradually but it is signed by rapid bursts of mobility characterized by relative compact clusters of mobile particles. These events (which have been named d clusters) are fast and sparse and trigger the transitions the system experiences between metabasins (MB) of its potential-energy surface. The MB residence times are much larger than the time scales of occurrence of the d clusters, and it has been suggested that the events that occur within them scarcely contribute to the structural relaxation of the system. Thus, the picture of glassy relaxation that emerges would indicate that at any time a supercooled liquid may present different spatial regions, each one characterized by different structural relaxation times. In turn, each of such regions would not relax smoothly or gradually but by means of sporadic sharp relaxation events. Here, we assess for a model glass former the relative relevance of the MB exploration events and of the d clusters both in small systems and within regions of large systems, to show that the structural relaxation at the region level is indeed extremely heterogeneous in time and utterly governed by the latter. © 2009 The American Physical Society.
Palabras clave:
Supercooled Liquids
,
Relaxation
,
Dynamical Heterogeneities
,
Glassy Liquid
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Articulos(INQUISUR)
Articulos de INST.DE QUIMICA DEL SUR
Articulos de INST.DE QUIMICA DEL SUR
Citación
Alarcon, Laureano Martin; Frechero, Marisa Alejandra; Montani, Ruben Alfredo; Appignanesi, Gustavo Adrian; Determining the heterogeneity in time of the dynamics within a slowly relaxing region of a supercooled liquid: Role of sharp relaxation events; American Physical Society; Physical Review E: Statistical, Nonlinear and Soft Matter Physics; 80; 2; 26-8-2009; 26127-26135
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