Scanning electronic microscope
Electron microscopy is a versatile tool with a range of methodologies to characterize the microstructural features of a sample from 100pm to 100μm length scales.
The SEM scans the surface of the sample with a high-energy electron beam. When the incident beam of electrons hits the specimen, X-rays and three types of electrons are emitted: backscattered (or primary) electrons, secondary electrons, and Auger electrons.
SEM makes use of the primary, or backscattered, and the secondary electrons. High-resolution images are produced by SEM revealing details of around 1–5 nm using the secondary electrons. For identifying elemental compositions, characteristic X-rays are used by a technique known as EDX. The backscattered electrons are also used to form the image in this technique.
ZEISS EVO 25 electron microscope
EVO 25 is the industrial workhorse solution with enough space to accommodate even the largest parts and assemblies.
EVO excels at extracting the maximum data quality from uncoated and unaltered samples. EVO also safeguards data quality on hydrated and heavily contaminated samples, by allowing these samples to remain in their native state. Additionally, the LaB6 emitter will give that extra bit of resolution, contrast and signal-to-noise that is important when imaging and microanalysis get challenging. EVO 25 has a stage that can handle weights up to 2 kg even with tilt. Additionally, the large chamber will accommodate multiple analytical detectors for the most demanding microanalysis applications.
Electron Microscope Analyzers
Our electron microscopes are equipped with a unique range of analysis methods for materials characterization on electron microscopes: EDS, WDS, EBSD and Micro-XRF.
X-Ray Fluorescence (XRF)
This technique uses an X-ray source that is angled at the coated substrate and the solid state energy dispersion sensor is arranged at the complimentary angle to collect the X-ray fluorescence (XRF). The X-rays cause electrons to be ejected followed by a movement of electrons into the electron vacancies resulting in an electron relaxation which is accompanied by an emission of X-rays known as X-ray fluorescence. These X-rays are material dependent and so the composition of compounds can be determined.
Energy Dispersive X-Ray Spectroscopy (EDS)
Energy-dispersive X-ray spectroscopy (EDX) is used to analyse the elemental composition of solid surfaces. X-ray emission is stimulated by the irradiation of the surface with a high energy beam of charged particles or a focused X-ray beam. Excitation of the electronic structure of an atom can produce an X-ray emission, the energy signature of which is a unique characteristic of each element. Therefore a “fingerprint” or “signature” spectrum can be obtained allowing element identification via comparison with reference spectra.
Electron Backscatter Diffraction (EBSD)
The data collected with EBSD is spatially distributed and is visualised in maps and images, and is powerful for looking at localised features or non homogeneous samples. It can be used to study specific grains, local texture changes and low volume phases. EBSD can provide good phase discrimination, and when used in conjunction with EDS (i.e. when the chemistry is also available) offers excellent phase identification.
Wavelength Dispersive X-ray Spectroscopy (WDS)
The WDS spectrometer can acquire the high count rate of X-rays produced at high beam currents, because it measures a single wavelength at a time. This is important for trace element analysis.