TEM characterization was performed at room temperature by using an FEI Titan 3 Themis operated at a 300 kV accelerating voltage. The FEI Titan 3 Themis S/TEM microscope was equipped with a high-brightness 'X-FEG' electron gun, an S-TWIN objective lens, a Gatan OneView 4K CMOS digital camera and a continuously variable gun lens to control the beam current. 'Low-dose' TEM was achieved by spreading the monochromator lens to reduce the electron flux to less than 1 e -/Å 2 s. SED data were acquired using a JEOL ARM300CF fitted with an ultrahigh-resolution pole piece, a cold field emission gun, and aberration correctors in both the probe forming and imageforming optics (Diamond Light Source, UK). The instrument was operated at 300 kV. A nanobeam configuration was obtained by switching off the aberration corrector in the probe forming optics and using a 10 μm condenser aperture to obtain a convergence semiangle <1 mrad and a diffraction-limited probe diameter of approximately 5 nm. The probe current was measured using a Faraday cup as 1 pA, and the exposure time was 600 μs or 1 ms per probe position. The estimated electron fluence for 600 μs dwell time, assuming a disk-like probe, was ~ 5 e -/Å 2 . A diffraction pattern was acquired at every probe position using a Merlin-Medipix hybrid counting-type direct electron detector (Quantum Detectors, UK).