Related papers: Local fluctuations in an aging glass
In this lecture we review several aspects of the thermal noise properties in two aging materials: a polymer and a colloidal glass. The measurements have been performed after a quench for the polymer and during the transition from a…
The electric thermal noise has been measured in two aging materials, a colloidal suspension (Laponite) and a polymer (polycarbonate), presenting very slow relaxation towards equilibrium. The measurements have been performed during the…
The noncrystalline glassy state of matter plays a role in virtually all fields of materials science and offers complementary properties to those of the crystalline counterpart. The caveat of the glassy state is that it is out of equilibrium…
We discuss the relaxation dynamics of a simple structural glass which has been quenched below its glass transition temperature. We demonstrate that time correlation functions show strong aging effects and investigate in what way the…
The fluctuation-dissipation relation (FDR) is measured on the dielectric properties a polymer glass (polycarbonate). It is observed that the fluctuation dissipation theorem is strongly violated for a quench from above to below the glass…
The presence of strong local fluctuations -- dynamical heterogeneities -- has been observed near the glass transitions of a wide variety of materials. Here we explore the possible presence of universality in those fluctuations. We compare…
Several papers have recently presented results of measurements of physical aging by studying the behavior of glassy materials quenched from temperatures above their glass transition temperature $T_g$. The evolution of the aging process is…
The emergence of nanoscience has increased the importance of experiments able to probe the very local structure of materials, especially for disordered and heterogeneous systems. This is technologically important; for example, the nanoscale…
The validity of fluctuation dissipation relations in an aging system is studied in a colloidal glass during the transition from a fluid-like to a solid-like state. The evolution of the rheological and electrical properties is analyzed in…
The aging behavior of polymer glass, poly(methyl methacrylate), has been investigated through the measurement of ac dielectric susceptibility ata fixed frequency after a temperature shift $\Delta T$ ($\le $ 20 K)between two temperatures,…
Response functions and fluctuations measured locally in complex materials should equally well characterize mesoscopic-scale dynamics. The fluctuation-dissipation-relation (FDR), relates the two in equilibrium, a fact used regularly, for…
The coefficient of static friction between solids generally depends on the time they have remained in static contact before the measurement. Such frictional aging is at the origin of the difference between static and dynamic friction…
The fluctuation-dissipation relation (FDR) is measured on the dielectric properties of a gel (Laponite) and of a polymer glass (polycarbonate). For the gel it is found that during the transition from a fluid-like to a solid-like state the…
Glass-forming liquids display strong fluctuations -- dynamical heterogeneities -- near their glass transition. By numerically simulating a binary Weeks-Chandler-Andersen liquid and varying both temperature and timescale, we investigate the…
Cooperative events requiring anomalously large fluctuations are a defining characteristic for the onset of glassy relaxation across many materials. The importance of such intermittent events has been noted in systems as diverse as…
We study the effect of physical aging on the mechanical properties of a model polymer glass using molecular dynamics simulations. The creep compliance is determined simultaneously with the structural relaxation under a constant uniaxial…
We report experimental measurements of particle dynamics in a colloidal glass in order to understand the dynamical heterogeneities associated with the cooperative motion of the particles in the glassy regime. We study the local and global…
Glasses are out-of-equilibrium systems aging under the crystallization threat. During ordinary glass formation, the atomic diffusion slows down rendering its experimental investigation impractically long, to the extent that a timescale…
Using a non-local Monte Carlo algorithm, we study the aging of a fragile glass, being able to follow it up to equilibibrium down to 0.89 Tmc (Tmc is the Mode-Coupling temperature) and up to unprecedentedly large waiting times at lower…
The relationship between the conductivity and the polarization noise is measured in a gel as a function of frequency in the range $1Hz - 40Hz$. It is found that at the beginning of the transition from a fluid like sol to a solid like gel…