Step 4: Determination of peak maxima: The radial intensity profile of ED patterns was subtracted from the radial intensity profile of the last diffraction pattern. The background-subtracted intensity profile of ED patterns with increasing cumulative doses is shown in fig. . The peak maxima of different Bragg planes were measured for the first ED pattern (I0) and the rest of the stack's ED patterns (I). The (I0/I) ratio provides the relative intensity of a specific Bragg plane as a function of cumulative dose. The relative intensity of a specific Bragg plane is 1 for the first ED pattern and gradually reduces to zero. The cumulative dose corresponding to 37 % reduction in the relative intensity is considered as a critical dose for a specific Bragg plane. TEM lens aberrations were corrected before the ED experiment to minimize elliptical distortions potentially present in ED patterns. A possible constant residual distortion present in the radial averaged ED peak intensities does not affect our measurements of the relative fading of Bragg plane intensities. Therefore, no further correction of the residual distortion was not performed in this analysis, though this would have been possible using the least-squares fitting method .