相关论文: Aging phenomena in PMMA thin films -- memory and r…
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…
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,…
Dynamics of thin films of poly(vinyl acetate) (PVAc) and poly(methyl methacrylate) (PMMA) have been investigated by dielectric relaxation spectroscopy in the frequency range from 0.1Hz to 1MHz at temperatures from 263K to 423K. The…
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…
Temperature cycling is used to study of aging properties of PMMA dielectric constant. If a negative temperature cycle is applied during the aging time the relaxation dynamics is just delayed for a time equal to the cycle period. In contrast…
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…
Glassy dynamics was investigated for thin films of atactic polystyrene by complex electric capacitance measurements using dielectric relaxation spectroscopy. During the isothermal aging process the real part of the electric capacitance…
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…
A new kind of memory effect on low frequency dielectric measurements on plexiglass (PMMA) is described. These measurements show that cooling and heating the sample at constant rate give an hysteretic dependence on temperature of the…
The glass transition temperature $T_g$ 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 dielectric…
We have compared aging phenomena in the Fe_{0.5}Mn_{0.5}TiO_3 Ising spin glass and in the CdCr_{1.7}In_{0.3}S_4 Heisenberg-like spin glass by means of low-frequency ac susceptibility measurements. At constant temperature, aging obeys the…
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.…
We study the effects of time-dependent substrate/film temperature in the deposition of a mesoscopically thick film using a statistical model that accounts for diffusion of adatoms without lateral neighbors whose coefficients depend on an…
Understanding the temperature dependence of the optical properties of thin metal films is critical for designing practical devices for high temperature applications in a variety of research areas, including plasmonics and near-field…
The memory effect in a single crystal spin glass ($\mathrm{Cu}_{0.92}\mathrm{Mn}_{0.08}$) has been measured using \freq ac susceptibility techniques over a temperature range of $0.4 - 0.7 \, T_g$ and a model of the memory effect has been…
We compare aging in a disordered ferromagnet and in a spin glass, by studying the different phases of a reentrant system. We have measured the relaxation of the low-frequency ac susceptibility, in both the ferromagnetic and spin-glass…
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,…
It was experimentally found that the evolution of dielectric loss with processing temperature displays a common trend in ferroelectric and dielectric thin oxide films: firstly an increase and then a decrease in dielectric loss when the…
We present new experimental results on the dielectric constant in orientational glasses K$_{1-x}$Li$_x$TaO$_3$ (KLT) with x < 0.05, together with the detailed (analytic and numerical) study of a model which attributes the observed aging to…
Modeling deformation at elevated temperatures using discrete dislocation dynamics (DDD) is a recent area of high interest. However, the literature dedicated to this subject fails to address the variations of DDD parameters with temperature.…