One of the unique features of the CCEM is its varied suite of instruments. We have, at one site, transmission electron microscopes (TEMs), scanning electron microscopes (SEMs), a focused ion beam (FIB) instrument, an atomic force microscope (AFM), instruments for atom probe tomography (APT) and Auger electron spectroscopy. We also have sample preparation facilities for a wide variety of materials.
Transmission Electron Microscopy
Transmission electron microscopy is a microscopy technique that operates similarly to light microscopy but uses electrons instead of light and is capable of a much higher resolution. A beam of electrons is focused using electromagnetic lenses through an ultra-thin specimen; a variety of detectors allows collection of images of structural details of the specimen and chemical information down to the atomic level.
FEI Titan 80-300 HB
Ultra high resolution TEM/STEM
FEI Titan 80-300 LB
High resolution HRTEM/STEM
General purpose TEM for imaging and diffraction
TEM/STEM optimized for analytical microscopy
Scanning Electron Microscopy
Scanning electron microscopy employs a focused beam of high-energy electrons which interact with atoms in the sample to generate a range of signals that can reveal information regarding the sample’s surface topography, chemical composition, crystallinity, orientation of materials and other many other characteristics. The magnification ranges from 20X to 30 000X and can be used to spatially resolve up to 50nm. The SEM can also perform qualitative or semi-quantitative point analyses at specific locations on the sample to determin chemical compositions (using energy-dispersive X-ray spectroscopy, EDS/EDX) or crystalline structure and crystal orientations (using electron backscatter diffraction, EBSD).
FEI Magellan 400
Extreme high-resolution SEM with sub-nanometer resolution
Optimised for analysis of non-conductive specimens, larger samples
Schottky Field Emission Gun-equipped SEM with high resolution
Focused Ion Beam
The focused ion beam is a technique that uses a beam of ions to directly modify or “mill” the specimen surface. This instrument is increasingly used in the semiconductor industry, materials science and biological field for site-specific analysis, deposition, and ablation of materials. The milling can be controlled with nanometer precision by careful control of energy and intensity of the ion beam, making it possible to perform precise, nano-machining to deposit material or remove unwanted material.
Paired with an SEM, the FIB at the CCEM can allow immediate, high resolution SEM imaging of the FIB-milled surface.
Cross-beam instrument with FIB milling and SEM imaging
Atomic Force Microscopy
Atomic force microscopy is a sensitive technique for measuring surface topography on a very fine scale. Surface steps as low as one atom high can be detected; the lateral resolution is equivalent. The lack of any requirement for a vacuum environment means that this technique is quick and versatile. An AFM works by scanning a sharp tip at the end of a cantilever over the surface of a sample while monitoring the deflection of the cantilever using a reflected laser. A map is built up of the topography of the surface as the tip is scanned.
NanoScope IIIa AFM
A compact, versatile AFM for high-resolution surface mapping
Atom Probe Tomography
Atom probe tomography allows 3-dimensional mapping of the composition of a selected volume of material at sub-nanoscale resolution. The technique requires specialized sample preparation; the method is somewhat onerous, but provides the advantage of being able to select exactly the volume of interest for analysis. APT is a very sensitive technique; it can detect elements down to near-ppm levels.
Combining APT analysis with electron microscopy allows for complete characterization of structure, composition, and distributions of most microstructural features.
Cameca LEAP4000X HR
Allows for 3D analysis of materials at sub-nanometer scale
Auger Electron Spectroscopy
In AES a beam of electrons is directed at the surface of the sample and, as result of primary and secondary interactions within the atoms of the material, x-rays and Auger electrons are emitted. The energy carried by an Auger electron is characteristic of the atom, the element, from which it came so an electron energy spectrometer can be used to detect an Auger electron energy spectrum, which is used for elemental analysis of the sample. Because of the low energies of Auger electrons, an ultra-high vacuum environment is required in the instrument and only electrons emitted from close to the surface of the material are not re-absorbed.
Auger electron spectroscopy is, however, a very sensitive technique for surface analysis, with a detection limit on the order of 1% of a monolayer. It can be used for quantitative analysis and mapping.
JEOL JAMP-9500F FE-Auger
High spatial resolution and high sensitivity surface analysis
Prior to using the microscopes, sample preparation to clean and coat the sample may be necessary. At the CCEM, we have technicians who can provide service and assistance with a range of sample preparation techniques including polishing, cutting, cleaning, coating and many more.
Please contact the facility manager for more information.