Related papers: Glassy dynamics in thin films of polystyrene
The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the…
We measure the isothermal rejuvenation of stable glass films of poly(styrene) and poly(methylmethacrylate). We demonstrate that the propagation of the front responsible for the transformation to a supercooled-liquid state can serve as a…
Aging dynamics in thin films of poly(methyl methacrylate) (PMMA) have been investigated through dielectric measurements for different types of aging processes. The dielectric constant was found to decrease with increasing aging time at an…
The glass transition temperature $T_{\rm g}$ and the temperature $T_{\alpha}$ corresponding to the peak in the dielectric loss due to the $\alpha$-process have been simultaneously determined as functions of film thickness d through…
We present a study of orientational relaxation dynamics in thin films of a low-molecular-weight glass-former as a function of temperature and film thickness. The relaxation is probed by second-harmonic generation after release of a poling…
The rate of physical aging of glassy polymethylmethacrylate (PMMA), followed from the change in the secondary relaxation with aging, is found to be independent of the density, the latter controlled by the pressure during glass formation.…
Dielectric relaxation and thermal expansion spectroscopy were made for thin polystyrene films in order to measure the temperature $T_{\alpha}$ corresponding to the peak in the loss component of susceptibility due to the $\alpha$-process and…
We report on the rejuvenation of thin films of polystyrene (PS) as they are heated from stable glassy states - prepared either through vapour deposition or physical aging. For films with thickness $h \gtrsim 200$ nm, the rejuvenation of…
In this paper, we review the general features of the out-of-equilibrium dynamics of spin glasses. We use this example as a guideline for a brief description of glassy dynamics in other disordered systems like structural and polymer glasses,…
We present a new set of electrical field effect measurements on granular aluminium insulating thin films. We have explored how the conductance relaxations induced by gate voltage changes depend on the age of the system, namely the time…
The $\alpha$-process (segmental motion) of thin polystyrene films supported on glass substrate has been investigated in a wider frequency range from 10$^{-3}$ Hz to 10$^4$ Hz using dielectric relaxation spectroscopy and thermal expansion…
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…
We are interested in the out of equilibrium phenomena observed in the electrical conductance of disordered insulators at low temperature, which may be signatures of the electron coulomb glass state. The present work is devoted to the…
We present time-dependent dielectric loss data at different frequencies for a variety of glass formers after cooling below the glass temperature. The observed aging dynamics is described using a modified Kohlrausch-Williams-Watts law, which…
We examine the structural relaxation of glassy materials at finite temperatures, considering the effect of activated rearrangements and long-range elastic interactions. Our three-dimensional mesoscopic relaxation model shows how the…
We present new results obtained by field effect measurements on insulating granular Al thin films. First, reproducible and stable conductance fluctuations are seen in micron size samples as a function of gate voltage. The anomalous field…
We observe non-monotonic aging and memory effects, two hallmarks of glassy dynamics, in two disordered mechanical systems: crumpled thin sheets and elastic foams. Under fixed compression, both systems exhibit monotonic non-exponential…
Low frequency dielectric measurements on plexiglass (PMMA) show that cooling and heating the sample at constant rate give an hysteretic dependence on temperature of the dielectric constant $\epsilon$. A temporary stop of cooling produces a…
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 show numerically that a three-dimensional model for structural glass displays aging, rejuvenation and memory effects when submitted to a temperature cycle. These effects indicate that the free energy landscape of structural glasses may…