Transmission Electron Microscopy
The JEOL JEM2011 transmission electron microscope (TEM) can be used to image a wide variety of materials at very high magnifications and is ideal for X-ray microanalysis of nanoscale structures. Specimens can be readily magnified up to 1.5 million times, achieving images with a spatial resolution of 0.14 nanometres.
The JEOL 2011 TEM is equipped with a high quality CCD camera enabling instant recording of high resolution digital images, which can then be exported in common image file formats compatible with most graphics software and online applications.
A convenient TEM sample preparation laboratory is available to all users, with staff to assist with sample preparation requirements.
Imaging - The information gained from TEM images differs substantially to images from SEM and other surface analysis techniques. The contrast in TEM images arises because of differences in the thickness and/or atomic mass within the specimen. In addition, regions of physical strain or atomic lattice defects can often be successfully observed using TEM since these regions also affect the way the electron beam interacts with the specimen.
In addition to imaging, the TEM can project electron diffraction patterns onto the screen or CCD camera. These patterns can be used to determine or confirm the crystal structure of a wide variety of materials.
STEM Imaging and Mapping
In Scanning TEM (STEM), instead of illuminating the entire sample all at once and collecting the magnified image on CCD camera or film, the lenses can focus the electron beam to a tiny nanoscale spot (as small as 0.3 nanometres), which can then be continuously scanned or rastered back and forth across the sample.
The significant advantage the STEM technique has over other nanometre-scale imaging is that, when used in conjunction with the EDS X-ray detector, chemical profile mapping can be performed on a nanometre scale, giving almost one thousand times better resolution than that of X-ray analysis using the SEM.
STEM mapping is particularly relevant for:
- analysing cross-sections of coated, graded or layered materials
- observing changes in chemistry across grains or along grain boundaries
- pinpointing areas of heavy metal dopant accumulation in biological systems.
Scanning Electron Microscopy | Transmission Electron Microscopy | Optical Microscopy | Image Analysis | Small Angle X-ray Scattering | X-ray Diffraction | X-ray Analysis | Corrosion Testing
