INVESTIGADORES
FRECHERO Marisa Alejandra
artículos
Título:
Determining the heterogeneity in time of the dynamics within a slowly relaxing region of a supercooled liquid: Role of sharp relaxation events.
Autor/es:
ALARCÓN L. M; FRECHERO M. A.; MONTANI R. A; APPIGNANESI G. A.
Revista:
PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS
Editorial:
APS
Referencias:
Año: 2009 vol. 80 p. 26127 - 26136
ISSN:
1063-651X
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.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.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.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.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.