Scanning Electron Microscopy is a technique which is used to study surface morphology and particle characterization. The focussed beam of electrons scans the surface of the material/sample. The high magnification, high-resolution imaging is achieved by using Field Emission Scanning Electron Microscopes (FESEM) which can resolve samples to 10nm. SEM analysis is used to determine quantity, size, and morphology of micron and sub-micron (nano) particles. The source of electrons in a regular SEM is tungsten or Lanthanum hexaboride filament which is heated to release electrons whereas FESEM uses a field emission gun to generate electrons.
A variety of materials such as nanoparticles, polymers, thin films, packaging material, minerals, metals, catalyst and biological samples can be analysed by SEM testing. For biological samples Environmental Scanning Microscope (ESEM) is used as in conventional SEM instrument vacuum is present inside the chamber where as in ESEM the sample image can be taken under variable environment.
Energy Dispersive Spectroscopy (EDS) is one of the major detectors used in SEM to understand the composition of the sample. It helps to identify whether any foreign material is present on the surface or to know the elemental makeup of the sample. The characteristic X-Rays of the elements are detected by the EDS detector and the software gives the spectrum accordingly. Elemental mapping is done to visualize the distribution of elements across a sample. This is very useful to qualitatively determine the presence of compounds in a particular sample during SEM analysis. Elements above carbon can be detected.
Electron Backscatter Diffraction (EBSD) technique is used for crystallographic study of a sample. EBSD detectors are attached to a SEM to capture backscattered electrons. A pattern is detected by the fluorescent screen when the electron beam falls on the tilted sample. With the help of these patterns the grain boundary and phase study of the material is obtained. Grain Structure, Grain Boundary characteristics, Deformation and Crystal Orientation can be studied through EBSD.
Sprint Testing Solutions provides SEM testing with expertise in high magnification imaging. We prepare samples with great care to achieve the best resolution of images. Our channel of SEM labs in India have the capability to resolve upto 10nm. These high end tests are performed by working professionals having years of experience in microscopic analysis.