Surface analysis

Energy Dispersive X-Ray Spectroscopy (EDS) is an analytical technique which provides surface elemental analysis and is available on our Transmission Electron Microscope (TEM), Scanning Transmission Electron Microscope (STEM), Focused Ion beam /SEM(Dualbeam) and all our Field Emission Gun Scanning Electron Microscopes

When an electron beam interacts with a specimen characteristic X-rays are produced. The energy and number of the X-rays emitted can be measured using an EDS detector.

Within AMF all the EDS detectors are silicon drift detectors and therefore can achieve a highcount rate, which reduces the acquisition time. It also provides the ability to reduce the beam current which will reduce the interaction volume produced by the electron beam and provide better resolution for the lighter elements such as Carbon and Boron.

Our ZEISS Sigma 300VP FEGSEM situated in the School of Geology, Geography and the Environment, has the ‘Mineralogic’ software platform for Automated Quantitative Mineralogy (AGM). This allows samples to be fully characterised based on the chemical composition of the discrete mineral/crystal phases present. Data outputs include quantitative mineral proportions, textural associations and phase contact relationships, target element deportment and phase liberations.

Wavelength-dispersive X-ray spectroscopy (WDXS or WDS) is a method used to count the number of X-rays of a specific wavelength diffracted by a crystal. The wavelength of the impinging X-ray and the crystal's lattice spacings are related by Bragg's law and produce constructive interference if they fit the criteria of Bragg's law. Unlike the related technique of energy-dispersive X-ray spectroscopy (EDS), WDS reads or counts only the X-rays of a single wavelength at a time, not producing a broad spectrum of wavelengths or energies simultaneously. WDS is primarily used in chemical analysis and has much higher accuracy and sensitivity than EDS analysis. For WDX samples should be flat and parallel on both sides, with one face well-polished.

• Wide area mineral mapping (e.g. 5 mm wide maps)
• Micro XRF analysis
• Cathodoluminescence