Ryu Chae Woo, Dmowski Wojciech, Egami Takeshi
Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev E. 2020 Mar;101(3-1):030601. doi: 10.1103/PhysRevE.101.030601.
It is difficult to characterize by experiment the structural features of liquids and glasses which lack long-range translational periodicity in the structure. Here, we suggest that the height and shape of the first peak of the structure function S(Q) carry significant information about the nature of the medium-range order and the coherence of density correlations. It is further proposed that they indicate how ideal the liquid structure is. Here, the ideal state is defined by long-range density correlations, not by structural coherence at the atomic level. The analysis is applied to the S(Q) of metallic alloy liquids determined by x-ray diffraction and simulation. The ideality index defined here may provide a common parameter to characterize structural coherence among various disparate groups of liquids and glasses.
通过实验来表征液体和玻璃的结构特征是困难的，因为它们在结构上缺乏长程平移周期性。在此，我们表明结构函数S(Q)的第一个峰的高度和形状携带了关于中程有序性质和密度相关性相干性的重要信息。进一步提出，它们表明了液体结构的理想程度。这里，理想状态是由长程密度相关性定义的，而不是由原子水平的结构相干性定义的。该分析应用于通过x射线衍射和模拟确定的金属合金液体的S(Q)。这里定义的理想指数可能提供一个共同参数来表征各种不同液体和玻璃组之间的结构相干性。
