Transmission Electron Microscopy is an analytical technique using electron where the beam of electrons are bombarded on a sample and those transmitted through the sample are detected to study the material structure and composition . To transmit the electron beam through sample, sample should be thin, around 300nm or less. The electron beam having energy around 100-300kev is used. The chamber in TEM has to be housed containing vacuum. It allows to avoid any contamination while analysis. The highest resolution of Transmission Electron Microscope is 0.050nm which is achieved through high end HRTEM.
Morphological, crystallographic and compositional information can be obtained from TEM analysis. For the crystal structure, SAED pattern is one of the crucial techniques. Selected Area Electron Diffraction (SAED) is the diffraction pattern formed when the electrons are diffracted, which results in the formation of dark background and bright spots.
TEM analysis of powder samples is done by usually using copper grid as sample holder. The nanopowder is first sonicated in the desired solvent and then placed on the grid. The dried conducting sample is then placed on the sample holder inside the chamber. The sample requirement for TEM analysis is around 10mg. For solid samples or thin film sample, it is preferred that the thickness of sample should not exceed 300nm of thickness.
FFor high magnification studies of nanomaterials High Resolution TEM is preferred. HRTEM testing provides images at atomic scale level.
Similarly to SEM , EDS Mapping can be done in TEM for compositional and elemental distribution study in material. Following are the different detectors that are used in TEM-
EDAX detector for detecting composition of sample, /STEM mode
Annular Dark field detector for High Angle Annular Dark Field Imaging(HAADF)
Charge Couple Detectors (CCD) for TEM/HRTEM Imaging
Sprint Testing Solutions provides access to high end TEM labs in India with state of the art TITAN TEM , HRTEM and TEM. EDS colour mapping can also be done with this sophisticated instrument along with the line scanning. Our experts provide best solution and advice for your sample testing requirement.