3. (8 points) The questions refer to the paper by Zhou et al. J. Catalysis, 229 (2005) 206. As described in the lecture on electron diffraction, the lattice plane in real space is always normal to the reciprocal lattice spot. When presenting such data for publication, we may sometimes need to rotate the diffraction pattern to make sure this relationship is obeyed. For example, in Fig. 7 the lattice fringe spacing of 0.19 nm corresponds to the {220} family of planes, which would lie normal to the [110] direction arrowed in the figure below. Examine the images in Fig. 8 (shown on the next page). a. The fringe spacing in Fig. 8a is indexed as 0.27 nm. Is the corresponding reciprocal lattice spot seen in the accompanying diffraction pattern (Fig. 8b)? Explain your answer. b. Comment on the authors' identification of the morphology of these rods (Fig. 8e) and explain whether you think the suggested shape is consistent with the contrast in the images in Fig. 8a and 8c. a b 002 020 [110] 0.19nm 30nm 20nm Fig. 7. (a) The cross-sectional TEM image of the CeO, nanorods; (b) HKTEM image of one typical CeO, nanorod. (The upper right inset shows a selected area electron diffraction (SAED) pallem from the rumored; the lower insel shows a magnified view of the selected ares of the nanorod.)