  In complex electronic materials, coupling between electrons and the atomic
lattice gives rise to remarkable phenomena, including colossal
magnetoresistance and metal-insulator transitions. Charge-ordered phases are a
prototypical manifestation of charge-lattice coupling, in which the atomic
lattice undergoes periodic lattice displacements (PLDs). Here we directly map
the picometer scale PLDs at individual atomic columns in the room temperature
charge-ordered manganite Bi$_{0.35}$Sr$_{0.18}$Ca$_{0.47}$MnO$_3$ using
aberration corrected scanning transmission electron microscopy (STEM). We
measure transverse, displacive lattice modulations of the cations, distinct
from existing manganite charge-order models. We reveal locally unidirectional
striped PLD domains as small as $\sim$5 nm, despite apparent bidirectionality
over larger length scales. Further, we observe a direct link between disorder
in one lattice modulation, in the form of dislocations and shear deformations,
and nascent order in the perpendicular modulation. By examining the defects and
symmetries of PLDs near the charge-ordering phase transition, we directly
visualize the local competition underpinning spatial heterogeneity in a complex
oxide.
