Chattopadhyay Sudeshna, Uysal Ahmet, Stripe Benjamin, Evmenenko Guennadi, Ehrlich Steven, Karapetrova Evguenia A, Dutta Pulak
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
Phys Rev Lett. 2009 Oct 23;103(17):175701. doi: 10.1103/PhysRevLett.103.175701. Epub 2009 Oct 22.
Pentaphenyl trimethyl trisiloxane is an isotropic liquid at room temperature with a dynamic glass transition at 224 K. Using x-ray reflectivity, we see surface density oscillations (layers) develop below 285 K, similar to those seen in other metallic and dielectric liquids and in computer simulations. The layering threshold is approximately 0.23 times the liquid-gas critical temperature. Upon cooling further, there is a sharp increase at 224 K in the persistence of the surface layers into the bulk material, i.e., an apparently discontinuous change in static structure at the glass transition.
五苯基三甲基三硅氧烷在室温下是各向同性液体，在224 K时有动态玻璃化转变。利用X射线反射率，我们发现在285 K以下会出现表面密度振荡（层），这与在其他金属和介电液体以及计算机模拟中观察到的情况类似。分层阈值约为液-气临界温度的0.23倍。进一步冷却时，在224 K时表面层向块状材料的持续性会急剧增加，即在玻璃化转变时静态结构出现明显的不连续变化。
