论文标题
在压力变化下结构松弛与扩散玻璃形成液体之间的耦合
Coupling between structural relaxation and diffusion in glass-forming liquids under pressure variation
论文作者
论文摘要
我们从理论上研究了使用弹性集体非线性兰格文鸟方程（ECNLE）理论和分子动力学（MD）模拟在不同压力下在不同压力下的结构弛豫和激活的扩散。外部压力限制了单个分子在其笼子内的局部运动，并触发了合作迁移率的减慢。尽管欧洲理论和仿真通常可以预测玻璃过渡温度的单调增加和压力的动态脆弱性，但模拟表明脆弱性降低是压力以上的1000 bar。发现结构放松时间与反扩散常数线性耦合。值得注意的是，这种耦合与压缩无关。理论计算与仿真量很高，并且与先前的工作一致。
We theoretically investigate structural relaxation and activated diffusion of glass-forming liquids at different pressures using both the Elastically Collective Nonlinear Langevin Equation (ECNLE) theory and molecular dynamics (MD) simulation. An external pressure restricts local motions of a single molecule within its cage and triggers the slowing down of cooperative mobility. While the ECNLE theory and simulation generally predict a monotonic increase of the glass transition temperature and dynamic fragility with pressure, the simulation indicates a decrease of fragility as pressure above 1000 bar. The structural relaxation time is found to be linearly coupled with the inverse diffusion constant. Remarkably, this coupling is independent of compression. Theoretical calculations agree quantitatively well with simulations and are also consistent with prior works.
