Notepad Corner

In scanning electron microscopy (SEM), a beam of electrons scans the surface of a specimen, providing detailed, magnified images. This is different to optical microscopy , which involves viewing objects through a magnified lens using visible light. Electron microscopy has certain advantages over optical microscopy. How Do Electron Microscopes Work? Using electron beams, an electron microscope can give a very high quality of imaging, as an advanced means of sample analysis. In SEM, an electron gun fires an electron beam which is focussed through a series of lenses and apertures on the microscope. When these beams hit the sample, they interact with atoms on its surface, emitting secondary electrons, backscattered electrons, and x-rays. The microscope has built-in detectors that pick up these signals, using them to create high-resolution images and provide information on the composition of the specimen. The SEM operates under vacuum conditions, which prevents atoms or mo...