Effect of dynamical heterogeneity on heat capacity at glass transition in typical silicate glasses
Effect of dynamical heterogeneity on heat capacity at glass transition in typical silicate glasses
复制标题
DOI：
10.1063/1.4939074
复制
发表时间：
2015-12
影响因子：
3.2
通讯作者：
Yun-liang Li;Liyun Zhao;Yue Sun;P. Wen;H. Bai;Wen-Qiong Wang
中科院分区：
文献类型：
--
作者：
Yun-liang Li;Liyun Zhao;Yue Sun;P. Wen;H. Bai;Wen-Qiong Wang
玻璃化转变时的热容跃变ΔCp和动力学不均匀性是玻璃形成液体的两个重要特征。为了揭示这两种性质之间的内在联系，通过系统测量ΔCp和过冷液相区的机械弛豫，研究了模型玻璃系统（Na 2 O）x（SiO2）1−x（x = 0.2-0.35）。发现ΔCp随Na 2 O含量的增加而线性增加，表明Na 2 O周围的局部快动力学对ΔCp的直接贡献。动力学非均匀性分析进一步证实了局部非均匀动力学与ΔCp之间的正相关性。我们的结果可能有助于理解玻璃化转变的本质。
The heat capacity jump ΔCp at glass transition and the dynamical heterogeneity are two of the most important features of glass forming liquids. In order to reveal the intrinsic relationship between the two properties, a model glass system (Na2O)x(SiO2)1−x (x = 0.2–0.35) was studied by the systematic measurements of the ΔCp and the mechanical relaxation in the supercooled liquid region. A linear increase in ΔCp with increasing content of Na2O was found, indicating direct contributions of the locally fast dynamics around Na2O to ΔCp. This positive correlation between the locally heterogeneous dynamics and ΔCp was further confirmed by the dynamical heterogeneity analyses. Our results might be helpful for understanding the nature of glass transition.