Schall Peter, Weitz David A, Spaepen Frans
Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, Netherlands.
Science. 2007 Dec 21;318(5858):1895-9. doi: 10.1126/science.1149308.
Structural rearrangements are an essential property of atomic and molecular glasses; they are critical in controlling resistance to flow and are central to the evolution of many properties of glasses, such as their heat capacity and dielectric constant. Despite their importance, these rearrangements cannot directly be visualized in atomic glasses. We used a colloidal glass to obtain direct three-dimensional images of thermally induced structural rearrangements in the presence of an applied shear. We identified localized irreversible shear transformation zones and determined their formation energy and topology. A transformation favored successive ones in its vicinity. Using continuum models, we elucidated the interplay between applied strain and thermal fluctuations that governs the formation of these zones in both colloidal and molecular glasses.
结构重排是原子玻璃和分子玻璃的基本特性；它们对于控制流动阻力至关重要，并且是玻璃许多性质演变的核心，例如其热容量和介电常数。尽管这些重排很重要，但在原子玻璃中无法直接观察到它们。我们使用胶体玻璃获得了在施加剪切力的情况下热诱导结构重排的直接三维图像。我们识别出局部不可逆剪切转变区，并确定了它们的形成能和拓扑结构。一个转变有利于其附近连续的转变。使用连续介质模型，我们阐明了施加应变和热涨落之间的相互作用，这种相互作用控制了胶体玻璃和分子玻璃中这些区域的形成。
