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首页> 外文期刊>The Journal of Chemical Physics >DYNAMICS OF GLASS-FORMING LIQUIDS .2. DETAILED COMPARISON OF DIELECTRIC RELAXATION, DC-CONDUCTIVITY, AND VISCOSITY DATA
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DYNAMICS OF GLASS-FORMING LIQUIDS .2. DETAILED COMPARISON OF DIELECTRIC RELAXATION, DC-CONDUCTIVITY, AND VISCOSITY DATA

机译：玻璃形成液的动力学.2。介电弛豫，直流电导率和粘度数据的详细比较

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We have studied the temperature dependence of dielectric relaxation times in terms of the peak frequency f(max)(T) of dielectric loss epsilon ''(omega) and the dc-conductivity sigma(dc)(T) of several glass-forming liquids, covering 12 decades in the peak. frequency f(max) and 9 decades in sigma(dc). Although de-conductivity samples the mobility of ionic tracers, its variation with temperature is similar to that of f(max)(T). The f(max)(T) and sigma(dc)(T) are analyzed using the temperature-derivative method and compared to the viscosity data eta(-1)(T). While most liquids reveal a common Vogel-Fulcher-Tammann (VFT) behavior for f(max), sigma(dc) and eta(-1) in an extended temperature range T greater than or equal to T-m, some liquids deviate from this behavior by displaying a crossover at T = T-A to an Arrhenius regime. In these cases the quantity f(max)(T) decouples from the common curves for sigma(dc)(T) and eta(-1)(T) and attains activation energies in excess (similar to 40% for alcohols) of those related to translational processes. For many samples a departure from the VFT behavior occurs at lower temperatures T-B < T-m which tends to retard the glass transition. The onset of this qualitative change in the temperature dependence at T-B turns out to be a characteristic temperature also in other experiments. (C) 1996 American Institute of Physics. [References: 39]
机译：我们已经研究了介电弛豫时间对温度的依赖性，它取决于介电损耗ε''ω的峰值频率f（max）（T）和几种玻璃形成液体的直流电σ（dc）（T） ，涵盖了12个高峰期。频率f（max）和9个十进制的sigma（dc）。尽管去电导率采样离子示踪剂的迁移率，但其随温度的变化与f（max）（T）相似。使用温度导数方法分析f（max）（T）和sigma（dc）（T），并将其与粘度数据eta（-1）（T）进行比较。尽管大多数液体在大于或等于Tm的扩展温度范围T中显示出f（max），sigma（dc）和eta（-1）的常见Vogel-Fulcher-Tammann（VFT）行为，但有些液体偏离了此行为通过在T = TA处显示与Arrhenius政权的交叉。在这些情况下，量f（max）（T）与sigma（dc）（T）和eta（-1）（T）的共同曲线解耦，并获得过量的活化能（类似于酒精的40％）与翻译过程有关。对于许多样品，在较低的温度T-B

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