## STEM If the beam is parallel, then we are operating in TEM mode; if the beam is converged, then it's STEM mode. It is pretty like SEM, but with significantly higher voltage, so the electron get transmitted. The signals are received not only by the upper detector, like SEM, but also the lower detectors. And due to the very small sample thickness, the damages are typically small. One very big benefits is, when we scanning every individual points, we obtain significantly more information about the sample. Therefore, we can easily capture both bright and dark field images at the same time, and gaming insights on the elements, by EDS or EELS. Detailed contents on these [[Detectors|detectors]] will be discussion later. An image captured during the practical session are shown here (JEOL F200, STEM mode). Both bright field and dark field images are captured simultaneously. ![[S01_Ptrod_JEOL DF_600kX_0002.jpg]]