Central Science Laboratory

Electron Microscopy and X-Ray Microanalysis

Sandy Bay Campus, Chemistry Building, Level 2, Rooms 217, 255, 256

This facility houses:

  • Cameca SX100 electron microprobe
  • FEI MLA650 environmental scanning electron microscope
  • Hitachi SU-70 field emission scanning electron microscope
  • Horiba XGT-7000V microXRF
  • digitised Olympus BX40F4 light optical microscope
  • BalTec SCD 050 sputter coater
  • Ladd 40000 and Dynavac CS300 carbon evaporators
  • Balzers CPD 030 critical point dryer

Electron Probe Microanalysis (EPMA) and Scanning Electron Microscopy (SEM) are closely related techniques for high-magnification imaging and spatially resolved chemical analysis of solid samples. Their focussed electron beam excites various secondary signals: Secondary electrons (SE) show surface morphology, backscattered electrons (BSE) local differences in mean atomic number, cathodoluminescence (CL) local variation in defect chemistry, x-rays are detected by wavelength and energy dispersive spectrometers (WDS, EDS) for chemical analysis. Whereas SEM is optimized for high-resolution microscopy, EPMA is mainly used for quantitative chemical analysis of micrometer-sized volumes, for which the samples have to be flat and polished. Non-conductive samples have to be coated (C, Au, Pt). Fresh biological specimens can be observed uncoated using the FEI in low vacuum or environmental mode. The microXRF uses a primary x-ray beam and EDS for lower resolution chemical microanalysis.

Contact Dr Karsten Goemann for more information

Electron Microscopy and X-Ray Microanalysis