论文标题
超冷金属液体中动力学的波矢量依赖性
Wave vector dependence of the dynamics in supercooled metallic liquids
论文作者
论文摘要
我们介绍了AU49CU26.9SI16.3AG5.5PD2.3和PD42.5CU27NI9.5P21靠近玻璃过渡温度的超冷液体。在只有少数原子间距离的先例未覆盖的空间范围内，使用X射线光子相关光谱法，我们表明显微镜结构弛豫过程在相相结构之后，在主要平均粒子间距离处有明显的速度。这种行为伴随着中间散射函数的形状发生巨大变化，这表明在长度尺度上存在大型动力学异质性，对应于几个粒子直径。颗粒运动的弹道样机制似乎决定了这两个系统在高粘性相中的结构弛豫，这可能与笼中的颗粒相符，与理论研究一致。
We present a detailed investigation of the wave vector dependence of collective atomic motion in Au49Cu26.9Si16.3Ag5.5Pd2.3 and Pd42.5Cu27Ni9.5P21 supercooled liquids close to the glass transition temperature. Using x-ray photon correlation spectroscopy in a precedent uncovered spatial range of only few interatomic distances, we show that the microscopic structural relaxation process follows in phase the structure with a marked slowing down at the main average inter-particle distance. This behavior is accompanied by dramatic changes in the shape of the intermediate scattering functions which suggest the presence of large dynamical heterogeneities at length-scales corresponding to few particle diameters. A ballistic-like mechanism of particle motion seems to govern the structural relaxation of the two systems in the highly viscous phase, likely associated to hopping of caged particles in agreement with theoretical studies.
