Abstract Scope |
With the introduction of high speed direct electron detectors, scanning transmission electron microscopy (STEM) can now record a full image of the diffracted electron probe scanned over the sample, producing a four-dimensional dataset we refer to as a 4D-STEM experiment. These diffraction images of the electron probe are extremely rich in atomic-scale information, such as the sample structure, orientation, composition, phonon spectra, defect structure and more. In this talk, I will discuss several 4D-STEM applications in materials science. I will show several examples of nanobeam electron diffraction used to measure sample structure, orientation and strain, for samples ranging from metallurgical alloys to conductive polymers. I will also describe phase contrast imaging methods such as differential phase contrast, ptychography and STEM holography. Each of these analyses can be performed with our open source py4DSTEM code. |