CAF
Welcome to Stellenbosch University

Scanning Electron Microscopy (SEM)

SEM.jpg​​

Instrumentation is available for high resolution imaging and identification of chemical signatures by SE/CL/BSD and EDS/WDS on a single specimen by Scanning Electron Microscopy. The available instruments can dynamically image partially wet, hydrated samples, with various detectors that can generate sharp images, analytical working distance can be variable from 2.0 to 20 mm without compromising any other functionality, 5-axis motorized stage can be fully tilted for imaging large samples with very uneven surface.

Please visit our blog: http://blogs.sun.ac.za/sem/.

Scanning Electron Microscopy

The unit is equipped with a ZEISS EVO MA15VP scanning electron microscope (SEM), as well as a LEO 1450VP SEM. Both the EVO MA15VP and LEO 1450VP SEM systems are equipped with following detectors for diverse applications:

  • Secondary Electron Detector (SED)
  • Variable Pressure Secondary Electron Detector (VPSED)
  • Backscattered Electron Detector (BSD)
  • Energy Dispersive X-ray Spectrometer (EDS or EDX: “GENESIS XM2”
  • Cathodoluminescence detector
  • Wave Dispersive X-ray Spectrometer (WDS) for more quantitative, in-situ elemental analysis.
Targets and Sample Preparation
The targets can be almost any type of solid materials having resistance to incident electron beam (‹30 kV). Common examples are metal, rock, soil, glass, plastic, polymer, fibre, ceramic, concrete, biological entities, or any combination of these.

This capability allows for users to perform SE/CL/BSD imaging and EDS/WDS analysis with least chemical contamination of the target – this aspect is important for some applications which require multiple experiments on a single specimen with minimal interference. If coating is desirable for your applications, the Gold Coater and Carbon Coater are available in the lab.

Transmission Electron Microscopy

The unit also houses a JEOL 1200-EX II transmission electron microscope (TEM) equipped with a new ORIUS™ SC 200 CCD camera. A TEM is ideal for a number of different fields such as life sciences, nanotechnology, medical, biological and material research, forensic analysis, gemology and metallurgy as well as industry and education. TEM provide topographical, morphological, compositional and crystalline information. The images allow researchers to view samples on a molecular level, making it possible to analyse.