Superresolution imaging of solids is essential to explore local symmetry breaking and derived material properties. Electron ptychography is one of the most promising schemes to realize superresolution imaging beyond aberration correction. However, to reach both deep sub-angstrom resolution imaging and accurate measurement of atomic structures, it is still required for the electron beam to be nearly parallel to the zone axis of crystals. Here, we report an efficient and robust method to correct the specimen misorientation in electron ptychography, giving deep sub-angstrom resolution for specimens with large misorientations. The method largely reduces the experimental difficulties of electron ptychography and paves the way for widespread applications of ptychographic deep sub-angstrom resolution imaging.

Sub-angstrom resolution imaging of porous materials like zeolites is important to reveal their structure-property relationships involved in ion exchange, molecule adsorption and separation, and catalysis. Using multislice electron ptychography, we successfully measured the atomic structure of zeolite at sub-angstrom lateral resolution for 100-nanometer-thick samples. Both lateral and depth deformations of the straight channels are mapped, showing the three-dimensional structural inhomogeneity and flexibility. Since most zeolites in industrial applications are usually tens to hundreds of nanometers thick, the sub-angstrom resolution imaging and accurate measurements of depth-dependent local structures with electron ptychography at low-dose condition will find wide applications in porous materials close to their industrially relevant conditions.

Interstitial solutes, such as carbon in steels, are effective solid‐solution hardening agents. These alloying elements are believed to occupy the octahedral interstices in body‐centered‐cubic (bcc) metals. Using deep‐sub‐angstrom‐resolution electron ptychography, here the first experimental evidence to directly observe individual oxygen atoms in a highly concentrated bcc solid solution—the (TiNbZr)86O12C1N1 medium‐entropy alloy (MEA)—is provided, whereby the interstitial sites in which the oxygen atoms are located are discerned. In addition to oxygen interstitials residing in octahedral sites, the first unambiguous evidence of a switch in preference to the unusual tetrahedral sites at high oxygen concentrations is shown. This shift away from octahedral occupancy is explained as resulting from the extra cost of strain energy when the requisite displacement of the host atoms is deterred in the presence of nearby octahedral interstitials.

Defects in crystals play a fundamental role in modulating mechanical, electrical, luminescent, and magnetic behaviors of materials. However, accurate measurement of defect structures is hindered by symmetry breaking and the corresponding complex modifications in atomic configuration and/or crystal tilt at the defects. Here, we report the deep-sub-angstrom resolution imaging of dislocation cores via multislice electron ptychography with adaptive propagator, which allows sub-nanometer scale mapping of crystal tilt in the vicinity of dislocation cores and simultaneous recovery of depth-dependent atomic structure of dislocations. The realization of deep-sub-angstrom resolution and depth-dependent imaging of defects shows great potential in revealing microstructures and properties of real materials and devices.

The twinning plane of crystals with a FCC structure is usually the (111) plane. Surprisingly, it was found that the twinning plane of CoO is (112).