Orientational order of liquids and glasses via fluctuation diffraction

摘要: Liquids, glasses and other amorphous matter lack long-range order, which makes them notoriously difficult to study. Local atomic order is partially revealed by measuring the distribution of pairwise distances, but this measurement insensitive orientational unable provide a complete picture diverse phenomena, such as supercooling glass transition. Fluctuation scattering with electrons X-rays able sensitivity, it obtain clear structural interpretations fluctuation data. Here we show that interpretation diffraction data can be simplified converting into real-space angular function. We calculate function from simulated nickel, generated classical molecular dynamics simulation quenching high temperature liquid state. compare results case initial state ideal f.c.c. lattice structure nickel. extracted distributions are rich in information about bond angles. The fluctuations potentially measurable electron sources also brightest X-ray sources, like free-electron lasers.