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Project

Advancing 4D STEM for atomic scale structure property correlation in 2D materials.

Defects such as dopants, vacancies and grain boundaries can dramatically alter the properties of 2D materials. Likewise new physical phenomena often emerge from interfaces between different materials. With 2D materials systems such interfaces can be laterally connected or stacked vertically, and exciting unexpected behaviors are emerging from both classes of interfaces. Understanding such systems requires knowledge of their local microscopic structure and composition. Electron ptychography and 4D STEM in general have recently experienced a renaissance as researchers realize the power of 4D STEM to provide local microscopic information that could not be directly accessed before. However 4D STEM, including ptychography, have previously been limited by the speed at which pixelated detectors could capture the required images, severely curtailing the speed at which 4D STEM could be performed. In this project we will overcome this limitation with our new 4D STEM detector which can operate hundreds of times faster than previous pixelated detectors. Using this breakthrough in speed we will develop superior means of not only imaging structure, but also atomic scale charge and field mapping, and extend such analysis into the third spatial dimension by combining 4D STEM with tomography and optical sectioning. Armed with these new tools we will enable a greater understanding of 2D material systems.
Date:1 Jan 2022 →  Today
Keywords:ELECTRON MICROSCOPY (TRANSMISSION)
Disciplines:Condensed matter physics and nanophysics not elsewhere classified