TEM stands for Transmission Electron Microscopy. It refers to a powerful imaging technique that utilizes a beam of electrons to examine the surface and internal structures of specimens at a microscopic level.
In a TEM, a sample is first thinly sliced, so that electrons can easily pass through it. The sample is then placed on a grid and inserted into the vacuum chamber of the microscope. Electrons are emitted from a heated filament at the source and accelerated through a series of electromagnetic lenses before reaching the specimen.
As the electron beam interacts with the atoms of the sample, it scatters, diffracts, and absorbs the electrons, creating a variety of signals. These signals are then detected and projected onto a fluorescent screen or a digital camera. By manipulating the electromagnetic lenses, the microscope enables high-resolution imaging, allowing researchers to observe the fine details and atomic arrangement of the specimen.
TEM has been widely used in various scientific fields, such as materials science, nanotechnology, and biology. It has allowed researchers to explore the microstructure and properties of materials, study the behavior of nanoparticles, investigate biological cells and organelles, and even examine viruses and other minute structures. By providing detailed information about the samples, TEM has greatly contributed to scientific discoveries, technological advancements, and our understanding of the microscopic world.
