Fluctuation microscopy: a probe of atomic correlations in disordered materials

Fluctuation microscopy is a new technique to study medium-range structure i n disordered materials. Low-resolution dark-field transmission electron mic roscope images are interpreted as spatially resolved diffraction maps. Stat istical analysis of intensity variations in these maps provides information about higher-order atom position correlation functions. Here we give a qua litative description of the technique and explore the properties and utilit y of higher-order correlation functions in describing the structure of diso rdered materials.