EM Labs
Contact: Dr Ben Buse
Kate Saunders
The electron microbeam laboratories provide a service to the Earth and Environmental science community as well as to all departments within the University of Bristol and beyond including external researchers and commercial work. The facility consist of a scanning electron microscope and an electron microprobe (EPMA), which provide a full range of electron and x-ray imaging, together with in-situ chemical analysis of both major and minor elements.
Scanning Electron Microscopy: Thermo Scientific Apreo 2 SE
The Thermo Scientific Apreo 2 SEM provides high performance imaging and analysis. The microscope is fitted with a field-emission source multiple detectors, including both retractable BSE and SE detectors and in-lens detectors of the trinity detection system. It also has the Thermo Scientific RGB cathodoluminescence detector.
The instrument has a range of charge mitigation strategies permitting high resolution analysis of uncoated non-conductive materials at high vacuum together with a low vacuum mode. The instrument is equipped with two Oxford Instrument energy dispersive detectors (EDS) providing rapid x-ray mapping and accurate non-normalised quantification either using factory standards or user calibrations.
Samples up to 110 mm can be accommodated, with stage movement in x, y and z, rotation and 105° tilt. The laboratories have the Alicona MEX software for stereographic measurement.
Electron Probe Microanalyser: JEOL JXA8530F EPMA
The Electron Probe Microanalyser (EPMA) is a non-destructive technique for the analysis of flat polished specimens. Non-conductive materials must be coated. Both spot analysis and area analysis in the form of chemical maps is possible.
Almost every element of the periodic table can be determined with the exception of those with atomic numbers lower than boron. Wavelength dispersive spectroscopy (WDS) provides improved spectral resolution and detection limits compared to EDS.
The JEOL JXA8530F EPMA is equipped with a Field Emission Gun electron source and thus provides the highest possible spatial resolution. The instrument has 5 wavelength dispersive spectrometers (WDS) and a energy dispersive spectrometer (EDS), integrated to allow quantification from both detectors.
It is equipped with both the JEOL software and the Probe for EPMA software providing additional features such as mean atomic number backgrounds and time-dependent intensities. The JEOL software permits mapping of irregular areas. The instrument is equipped with a Peltier-cooled cold finger to assist in reducing contamination when analysing at low voltage or low overvoltage to achieve high analytical resolution.
The samples are normally prepared as polished 1 - inch rounds polished short thin sections without glass cover slips. Please discuss samples before preparation.