Fluctuation microscopy: a probe of atomic correlations in disordered materials

Fluctuation microscopy is a new technique to study medium-range structure in disordered materials. Low-resolution dark-field transmission electron microscope images are interpreted as spatially resolved diffraction maps. Statistical analysis of intensity variations in these maps provides information about higher-order atom position correlation functions. Here we give a qualitative description of the technique and explore the properties and utility of higher-order correlation functions in describing the structure of disordered materials.