Uncertainties in Stereo Lattice Imaging

Abstract Three-dimensional reconstruction in TEM is an established technique in both electron diffraction crystallography and electron tomography [1,2]. By stereo lattice imaging, we refer to a different task: determination of unit cell parameters in 3D using only direct-space lattice images at two or more (often widely varying) orientations [3,4], This note concerns the uncertainties associated with lattice parameter determinations by this technique. in particular, for decreasing crystal thickness the broadening of reciprocal lattice spots increases one’s chances to visualize lattice fringes. At the same time, however, it introduces uncertainties in reciprocal lattice vector length and direction. In the following discussion, sources from which uncertainties arise are assumed to be uncorrected. Three sources of uncertainty for reciprocal lattice vectors which lie in the plane of the specimen stage (and hence can be imaged directly as fringes) are, in order of decreasing relative size as follows: