Scanning Electron Microscopy

Scanning electron microscopy is a technique used for imaging samples at a resolution of 20x-30,000x. SEM rasters an electron beam across the sample, so the should be electrically conductive to prevent charging. Samples are often mounted to a metallic stub via conductive carbon tape. Highly insulating samples can be made conductive by sputtering a thin layer of gold onto their surface. Most SEM's are coupled with electron dispersive X-ray spectroscopy, which can be used to identify elements heavier than lithium.