Detection of Atomic Order in Quasiamorphous Materials

The cross-correlation of intensity fields of different regions of an HREM micrograph can identify regions of structural order in an apparendy random matrix. This paper presents results of cross-correlations on computer-simulated HREM images of a diin Si crystallite located on a relatively thick slab of amorphous Si. These simulations confirm the efficacy of cross-correlations in retrieving atomic order from die image of an apparently amorphous material and thus confirm the interpretation of experimental results obtained earlier.