Secondary relaxation behavior in a strong glass
Secondary relaxation behavior in a strong glass
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DOI：
10.1021/jp711696p
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发表时间：
2008-07-31
影响因子：
3.3
通讯作者：
Yue, Yuanzheng
中科院分区：
文献类型：
--
作者：
Hu, Lina;Yue, Yuanzheng
本文研究了最强玻璃体系之一的GeO_2(HQGeO(2))超快冷玻璃的热焓松弛行为。通过应用超猝灭-退火量热方法，我们发现，与脆性玻璃不同，强HQGeO(2)玻璃的驰豫方式是所有的次级弛豫单元都有助于初级驰豫。通过分析二次弛豫的动力学性质，我们发现了HQGeO(2)玻璃中Johari-Goldstein弛豫的两个典型特征。首先，这里观察到的E-β和T-g之间的定量关系与JG弛豫的经验关系很好地吻合。其次，发现GeO2玻璃的特征弛豫时间约为10 S，大于相对易碎玻璃的特征弛豫时间。这些结果证实了强玻璃中的JG峰被介质损耗曲线中的α峰所掩盖。
In the present paper we study the enthalpy relaxation behavior of the hyperquenched GeO2 (HQGeO(2)) glass, one of the strongest glass systems. By applying the hyperquenching-annealing-calorimetry approach, we have found that unlike fragile glasses the strong HQGeO(2) glass relaxes in a manner that all the secondary relaxation units contribute to the primary relaxation. By analyzing dynamic properties of the secondary relaxation, we have identified two typical features of the Johari-Goldstein relaxation in the HQGeO(2) glass. First, the quantitative relationship observed here between E-beta and T-g agrees well with the empirical relation of the JG relaxation. Second, the characteristic relaxation time of the GeO2 glass at T. is found to be about 10 s, larger than that of relatively fragile glasses. These results verify that the JG peak in strong glasses is hidden by the alpha peak in the dielectric loss curves.