Applications and practical uses - what the TEM can do
The transmission electron microscope (TEM) is used to examine the structure, composition, and properties of specimens in submicron detail. Aside from using it to study general biological and medical materials, transmission electron microscopy has a significant impact on fields such as: materials science, geology, environmental science, among others.
The investigation of the morphology, structure, and local chemistry of metals, ceramics, and minerals is an important aspect of contemporary materials science. It also enables the investigation of crystal structures, orientations and chemical compositions of phases, precipitates and contaminants through diffraction pattern, characteristic X-ray, and electron energy loss analysis.
Transmission electron microscopy can:
- Image morphology of samples, e.g. view sections of material, fine powders suspended on a thin film, small whole organisms such as viruses or bacteria, and frozen solutions.
- Tilt a sample and collect a series of images to construct a 3-dimensional image.
- Analyse the composition and some bonding differences (through contrast and by using spectroscopy techniques: microanalysis and electron energy loss).
- Physically manipulate samples while viewing them, such as indent or compress them to measure mechanical properties (only when holders specialised for these techniques are available).
- View frozen material (in a TEM with a cryostage).
- Generate characteristic X-rays from samples for microanalysis.
- Acquire electron diffraction patterns (using the physics of Bragg Diffraction).
- Perform electron energy loss spectroscopy of the beam passing through a sample to determine sample composition or the bonding states of atoms in the sample.