Determining the radial pair-distribution function within intergranular amorphous films by numerical nanodiffraction

We report on an alternative method to electron nanodiffraction and fluctuation microscopy for the determination of the reduced density function G(r) of amorphous areas with small cross-sections. This method is based on the numerical extraction of diffraction data from the complex-valued exit-face wave function as obtained by HRTEM focal series reconstruction or electron holography. Since it is thus possible to obtain "diffraction data" from rectangular areas of any aspect ratio, this method is particularly suited for intergranular glassy films of only 1-2 nm width, but lengths of several 100 nm. A critical comparison of this method with the already established nanodiffraction and fluctuation microscopy will be made.