School of Geographical & Earth Sciences

Geoanalytical Electron Microscopy and Spectroscopy (GEMS) facility provides centimeter-to-nanometer scale imaging, chemical characterisation and detailed microstructural analysis of diverse materials, supporting research and development across geoscience, materials science, engineering, biology, and other fields requiring precise structural and compositional insights.

What we do

Our key techniques include:

• SEM imaging (SE, in-lens, BSE) - 2D imaging of topography and composition of material surfaces up to nano-scale.
• EDX analysis – rapid determination of elemental compositions of materials, including standard-based quantitative analysis.
• EBSD analysis - determination of crystal structures and high-speed mapping of crystallographic orientations for metals and minerals.
• Large area mapping – automated stage allows to acquire high-resolution image mosaics, EDX and EBSD maps of up to cm-size areas in the sample.
• Cathodoluminescence (CL) - acquisition of panchromatic CL images, often used for reconstruct growth histories of mineral grains based on trace element distribution or lattice defects.
• Raman spectroscopy – non-destructive material identification and characterisation, including mapping, based on the interaction of light with the chemical bonds within a material.

Facilities and equipment

Our instrumentation include:

• Zeiss Sigma FEG SEM equipped with:
  • Zeiss secondary electron (SE), gaseous secondary electron (GSE), InLens and backscatter electron (BSE) detectors
  • EDX detector - Oxford Instruments Ultim Max silicon drift detector with 170 mm2 sensor size
  • EBSD detector - Oxford Instruments Symmetry 2
  • WDS detector – Oxford Instruments Wave
  • Automated stage for large area mapping.
• Renishaw InVia Raman microscope equipped with 514 nm (green light) and 785 nm (red light) lasers.
• Quorum Q150T Plus coater capable of depositing nm-scale carbon- and Au/Pd (80:20) coating for SEM analysis.

We also provide training and support for visitors in data acquisition, processing and interpretation.