Figure 3: Determination of the electric field in the experimental study of SrTiO3.
From: Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction
(a) Experimental ronchigrams of SrTiO3 in a region of the unit cell recorded on CCD with 4 min acquisition time. Atomic sites as indexed in the Z-contrast image (inset) are easily identified in the 20 × 20 ronchigram array. Even the oxygen columns appear clear as marked by the yellow arrow. (b) Experimental momentum transfer obtained from equation (1) and the ronchigrams shown in a. Length of the black legend vector is 5h nm−1. (c) Electric field 
derived from the momentum transfer in b via equation (2) using the measured specimen thickness of z=2.5 nm, superimposed to the bright field intensity (BF Int.). Length of the black legend vector is 1 V pm−1. Scale bars top left in b,c are 100 pm.
