Fig. 2
Measuring the electric field using DPC on a universal detector. a DPC generated by Coulomb attraction between negatively charged beam and positively charged nucleus causing deflection of the electron beam that is observable on a universal detector. b HAADF detector image of DSO unit cell with three pixels marked corresponding to acquisitions at three probe positions. c–e The Ronchigrams from the 4D dataset corresponding to the top-left (P1—c), midpoint (P2—d), and bottom-right (P3—e) of the tilted Dy double column. The deflection of the electron beam is quantified by weighting the intensity in each pixel of the Ronchigram by the distance of that pixel with respect to the center of the bright field disk in the x- and y-directions (with one half being positive and the other negative for each direction). The new weighted Ronchigram is then integrated. The resultant value is the ICOM value of the pixel which is proportional the electric field at that probe position. The COM-weighted Ronchigrams for the probe positions of P1–P3 are shown in f–h, respectively with the direction and magnitude of the ICoM plotted as an arrow. (i) The direction and magnitudes of the field are plotted at each probe position in the across the entire unit cell