Puzenko Alexander, Ishai Paul Ben, Paluch Marian
Department of Applied Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
J Chem Phys. 2007 Sep 7;127(9):094503. doi: 10.1063/1.2768962.
The experimentally observed characteristic features of the alpha-relaxation process in glass-forming liquids are the non-Arrhenius behavior of the structural relaxation times and the non-Debye character of the macroscopic relaxation function. The Avramov model in which relaxation is considered as an energy activation process of surmounting random barriers in liquid energy landscape was successfully applied to describe the temperature and pressure dependences of the macroscopic relaxation times or viscosity. In this paper, we consider the dielectric spectrum associated with Avramov model. The asymmetrical broadening of the loss spectra was found to be related directly to dispersion of the energy barrier distribution. However, it turns out that temperature dependence of the spectrum broadening as predicted by the Avromov model is at odds to experimental observation in glass-forming liquids.
在玻璃形成液体中，α弛豫过程经实验观察到的特征是结构弛豫时间的非阿累尼乌斯行为以及宏观弛豫函数的非德拜特性。将弛豫视为液体能量景观中跨越随机势垒的能量激活过程的阿夫拉莫夫模型，已成功用于描述宏观弛豫时间或粘度的温度和压力依赖性。在本文中，我们考虑与阿夫拉莫夫模型相关的介电谱。发现损耗谱的不对称展宽与能垒分布的色散直接相关。然而，事实证明，阿夫拉莫夫模型预测的谱展宽的温度依赖性与玻璃形成液体中的实验观察结果不一致。
