Precise measurement of the electron beam current in a TEM.

Modern quantitative TEM methods such as the ζ-factor technique require precise knowledge of the electron beam current. To this end, a macroscopic Faraday cup was designed and constructed. It can replace the viewing screen in the projection chamber of a TEM and guarantees highly accurate measurement of the electron beam with precision only limited by the used amperemeter.

Electron ptychographic phase imaging of light elements in crystalline materials using Wigner distribution deconvolution.

Recent development in fast pixelated detector technology has allowed a two dimensional diffraction pattern to be recorded at every probe position of a two dimensional raster scan in a scanning transmission electron microscope (STEM), forming an information-rich four dimensional (4D) dataset. Electron ptychography has been shown to enable efficient coherent phase imaging of weakly scattering objects from a 4D dataset recorded using a focused electron probe, which is optimised for simultaneous incoherent Z-contrast imaging and spectroscopy in STEM. Therefore coherent phase contrast and incoherent Z-contrast imaging modes can be efficiently combined to provide a good sensitivity of both light and heavy elements at atomic resolution.

Rapid low dose electron tomography using a direct electron detection camera.

We demonstrate the ability to record a tomographic tilt series containing 3487 images in only 3.5 s by using a direct electron detector in a transmission electron microscope. The electron dose is lower by at least one order of magnitude when compared with that used to record a conventional tilt series of fewer than 100 images in 15-60 minutes and the overall signal-to-noise ratio is greater than 4.