Scanning Electron Microscopes (SEM)
Information on the FEI Helios Nanolab 600
The Helios Dualbeam was installed in Feb 2008 and is a flagship instrument of the AMMRF.
In a single instrument platform it combines a high resolution scanning electron microscope (SEM) with high resolution focussed ion beam (FIB).
The FIB uses a focused beam of Ga+ ions to sputter the surface of the sample to expose sub-surface features. The ion beam can also be used to form high resolution images if the beam current is kept low enough to avoid excessive surface sputtering.
The addition of a high resolution SEM allows the collection of electron induced signals from the exposed surfaces. These include secondary and back-scattered electron images, characteristic x-ray and electron back-scattered diffraction images for analysis of crystal structure,
crystallographic orientation and phase type. The instrument also has a solid state STEM detector allowing the imaging of very thin samples.
- Sample machining
- Sample cross-sections
- 3D microscopy
- Slice and view
- TEM foil preparation
- Atom probe needles
- Feature size measurement
- Site specific sample selection
- Sample selection, placement and shaping
- Micro-analytical investigating
- EDXS - Energy Dispersive X-ray Spectroscopy
- The collection of the emitted x-rays by a solid state detector and the measurement and display of their energy distribution. This makes possible the identification, quantification and mapping of elements in a solid sample.
- EBSD- Electron Back - Scattered Diffraction
- OIM - Orientation Imaging Microscopy
- The measurements of local orientation by the collection of patterns formed by diffraction of back - scattered electrons within the crystal structure
- ‘Delpi' - a program which allows the simultaneous collection of EBSD and EDXS data. This makes it Possible to use sample chemistry to aid in phase identification when materials have similar diffraction patterns.
For more details regarding the FIB's capabilities go to:
Information on the SEM FEI Quanta 450 FEG Environmental SEM + Oxford Ultim Max Large Area SDD EDS Detector
The FEI Quanta 450 is a High Resolution Field Emission Scanning Electron Microscope capable of operation in three different modes: High Vacuum, Low Vacuum and Environmental SEM (ESEM). As well as a standard sample stage, the instrument also has cooling, heating and tensile stages. The Quanta 450 is used to image and analyse surface topography and morphology, collect backscattered electron images and characterise and determine a sample's elemental composition via energy dispersive x-ray spectroscopy (EDS). It has an Oxford Ultim Max Large Area SDD EDS detector with Oxford AZtec EDS processing software and also has live mapping functionality.
- High Vacuum mode allows for high resolution imaging of surface topography (up to 1000000x magnification).
- Low Vacuum mode allows for imaging and characterisation of non-conductive samples.
- ESEM mode allows in situ imaging of wet samples, which is ideal for plant material and other biological specimens. It can also be used for in situ observation of processes such as hydration and dehydration, corrosion and crystallisation.
- X-ray analysis for determination of elemental composition with an Oxford Ultim Max Large Area SDD EDS detector with Oxford AZtec EDS processing software.
The stage has a lateral movement range of 100mm and a vertical movement range of 60mm.
Applications for the Quanta 450 are wide ranging and include imaging and microanalysis of metals, semiconductors, materials and their defects, coatings, particles, fibres and geological and biological samples.
Information on the SEM Philips XL30 FEG SEM + Oxford X-Max SDD EDS Detector, Oxford Cryo Stage, HKL EBSD
The Philips XL30 Field Emission Scanning Electron Microscope offers high resolution imaging, as well as low kV imaging for uncoated or insulating materials. The XL30 is used to image and analyse surface topography and morphology, collect backscattered electron images and characterise and determine a sample's elemental composition via energy dispersive x-ray spectroscopy (EDS). It has an Oxford X-Max SDD EDS detector with Oxford AZtec EDS processing software.
- Field emission electron source offers high-resolution imaging (up to 1000000x magnification).
- Solid state backscattered electron detector for mean atomic number imaging.
- X-ray analysis for determination of elemental composition with an Oxford X-Max SDD EDS detector and Oxford AZtec EDS processing software.
- Oxford Cryo-transfer and fracture stage, allowing biological and plant samples to be prepared for the vacuum chamber whilst restoring their integrity. (currently unavailable)
- Electron Backscattered Diffraction Pattern imaging with HKL EBSP camera.
The stage has a lateral movement range of 50 x 50 mm and a vertical movement range of 30mm. The recommended sample size is to fit onto a 12mm or 24mm diameter stub with maximum height of 5mm.
The scanning electron microscope (SEM) is used to image the surface of a sample. Like the transmission electron microscope (TEM), a SEM has an electron gun at the top of an electron optical column. The beam is focused into a small spot, which is scanned over the specimen in a raster pattern. The specimen is mounted in a vacuum chamber, which is very much larger than that in the TEM. Secondary (specimen) electrons are produced by the interaction of the beam with the sample, a positively biased detector collects these secondary electrons.
This signal is electronically converted into an image produced on a monitor, as the electron beam scans at the same scan rate of a cathode ray tube. The magnification is determined by the area of the sample scanned by the beam. The sample does not have to be thin like those for TEM, because the secondary electrons are emitted from the surface layer. Backscattered electrons, which are reflected (elastically scattered) electrons, whose contrast function is dependent on the mean atomic number of the surface atoms, produce images which give information about elemental distribution in the sample. Characteristic X-rays are also produced by the beam/specimen interaction, and these can produce elemental spectra and maps of the surface.
Information on the Hitachi FlexSEM 1000 SEM
The Hitachi Flex Scanning Electron Microscope FlexSEM 1000 IIM 1000 features a SE detector, high-sensitivity 4-segment BSE detector and UVB detector, and a pre-centred tungsten filament and accelerating voltages of 1-20 kV.
The ultra-variable-pressure detector enables observation of the surface of non-conducting specimens without coating.
Information on the Hitachi SU1510 SEM
The Hitachi SU1510 SEM is a tungsten filament SEM equipped with a secondary electron (SE) detector and a backscatter electron (BSE) detector.
The system allows for variable pressure operation which means non-conductive samples can be imaged uncoated.
With a sample stage that can accommodate samples up to 153mm in diameter the SU1510 is ideal as a pre-screening tool for high resolution SEM samples.