Atomically abrupt oxide interfaces

High-angle annular dark field images of a La0.7Sr0.3MnO3/SrTiO3 superlattice grown by pulsed laser deposition. The view is down the [100] zone axis of the SrTiO3 substrate. Right, a magnified view shows atomically sharp interfaces between the two materials.

Cryo-STEM mapping of solid-liquid interfaces in Li-metal batteries

Direct observation of the anode–electrolyte interface in a Li metal battery reveals two types of dendrite, one of which may contribute disproportionately to capacity fade.

Charge ordering - Bending and breaking of stripes

In charge-ordered phases, broken translational symmetry emerges from couplings between charge, spin, lattice, or orbital degrees of freedom, giving rise to remarkable phenomena such as CMR and MIT. To understand the role of the lattice in charge-ordered states, we directly map picometer scale periodic lattice displacements at individual atomic columns in the room temperature charge-ordered manganite using aberration-corrected STEM.

We measure transverse, displacive lattice modulations of the cations, distinct from existing manganite charge-order models. We reveal locally unidirectional striped domains as small as ~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 periodic lattice displacements near the charge ordering phase transition, we directly visualize the local competition underpinning spatial heterogeneity in a complex oxide.