β-relaxation has long been attributed to localized motion of constituent molecules or atoms confined to isolated regions in glasses. However, direct experimental evidence to support this spatially heterogeneous scenario is still missing. Here we report the evolution of nanoscale structural heterogeneity in a metallic glass during β-relaxation by utilizing amplitude-modulation dynamic atomic force microscopy. The successive degeneration of heterogeneity during β-relaxation can be well described by the Kohlrausch-Williams-Watts equation. The characteristic relaxation time and activation energy of the heterogeneity evolution are in accord with those of excess enthalpy release by β-relaxation. Our study correlates β-relaxation with nanoscale spatial heterogeneity and provides direct evidence on the structural origins of β-relaxation in metallic glasses.

中文翻译：

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金属玻璃中β松弛与空间异质性之间的内在联系。

长期以来，β松弛归因于局限于玻璃中孤立区域的组成分子或原子的局部运动。但是，仍然缺少支持这种空间异构场景的直接实验证据。在这里，我们通过利用振幅调制动态原子力显微镜观察报告了金属玻璃在β松弛过程中纳米级结构异质性的演变。β松弛过程中异质性的连续退化可以用Kohlrausch-Williams-Watts方程很好地描述。异质性演化的特征弛豫时间和活化能与通过β-松弛释放过量的焓相一致。