Improved visibility of thin amorphous intergranular films using Fourier filtering

Abstract. It is shown that the visibility of thin intergranular films or other non-periodic features in HRTEM micrographs can be enhanced by Fourierfiltering out the periodic information in the image. This is particularly useful in the case of the thinnest films where the visibility is very low in the raw HRTEM images. It is shown that the film thickness is typically underestimated in measurements from HRTEM images, whereas it is much more accurately represented in Fourier-filtered images, so long as the boundary tilt is minimised.