Electron-Beam Facilities

Test samples of coral and rocks in resin are loaded onto analysis tray with copper tape. The door is open to the Thermo Scientific Apreo 2 SEM in the Materials Department.

The Earth Sciences Department is proud to provide analysis using an Electron Microprobe (CAMECA SX-5 FE) and two Scanning Electron Microscopes (FEI Quanta 650 and Thermo Scientific Apreo 2) in its Electron-Beam (E-Beam) facilities. The E-Beam methods are used to study a wide range of natural and artificial solid materials, such as natural volcanic and synthetic glasses, minerals, experimental run products, solar cells, metal alloys and fossiliferous material.

The Scanning Electron Microscope (SEM) is typically employed in imaging surface morphology at sub-mm resolutions and studying major and minor element mapping and quantification using the energy dispersive X-ray spectrometers. The large sample chamber afforded by the SEM is ideal for larger samples (up to 30x30 cm) and its intuitive interface allows for rapid analysis.

The Electron Probe Micro Analyser (EPMA) is capable of high-resolution (~micron), fully quantitative minor and trace-element chemical analysis.

How We Can Support You

We can offer advice at any stage of the research process, including:

Advice on potential research approaches at the initial stages of inquiry
Logistics and scheduling
Aid in sample preparation
On-instrument training, calibration and x-ray modelling
Support when using the equipment and obtaining the data
Data interpretation and advice on data presentation

The Scanning Electron Microscopes and Electron Microprobe protocols can be precisely tailored to the needs of the researcher. The analytical precision of analyses will depend on the sample itself (composition, sample preparation etc.), the equipment conditions employed, and purpose of research, so please contact us with any questions.

Contact Information

Interested in using the E-Beam facilities? For rates, training, or to schedule use, please contact Andrew Matzen for the Electron Microprobe or Jon Wade for the Scanning Electron Microscopes.

The Earth Sciences Department has access to two Scanning Electron Microscopes (SEMs): a FEI Quanta 650 (installed in 2012) hosted in the Department of Earth Sciences, and a Thermo Scientific Apreo 2 S (installed in 2026) based in the Department of Materials’ David Cockayne Centre for Electron Microscopy. Both instruments are capable of imaging in various modes, as well as the compositional analyses of a range of natural and synthetic materials. Recent uses have included; mineralogical materials, both thin sections and unprepared materials, compositional analyses of high-temperature alloys, biogenic material (lab-grown and natural), extra-terrestrial materials and very high value gemstones.

Key Features

The Thermo Scientific Apreo 2 SEM system in the Materials’ David Cockayne Centre for Electron Microscopy

A field emission electron (FEG) source enabling stable, high-resolution imaging
Secondary and backscatter electron detectors (enabling both high – and low-vacuum work)
Oxford Instruments energy-dispersive x-ray spectroscopy (EDS) detector(s) system for rapid major and minor elemental characterization

Approaches and Outputs

High-resolution (sub-micron) imaging for surface topography (texture and shape) and internal composition
- Secondary electron imaging for high level surface morphology
- Backscattered electron imaging for mean atomic number composition (flat, polished samples) and surface topography
Energy-dispersive x-ray spectroscopy (EDS) for major and minor (typically >1000 ppm) elemental composition and mapping
Cathodoluminescence (CL) for electron beam induced light emission arising from certain mineral structures/compositions

Additional Features and Outputs from the Thermo Scientific Apreo 2 SEM

Twin 100mm-Oxford Instrument EDS systems for rapid major and minor elemental characterization, mapping and quantification (full standards-based or 'semi-quant')
In-column hybrid detectors for BSE and SE imaging, delivering much-improved imaging at low accelerating voltages (low kV_acc)
Low vacuum imaging and analyses for uncoated samples
A retractable BSE detector for highest mean atomic number contrast
Pseudo-colour CL detector
In-chamber plasma cleaner for sample surface preparation
5-axis stage for large samples (up to ~30x30cm)

Previous Research

Compositional analyses of Roman gold coins
Meteorite and lunar (Apollo) return samples
High pressure experimental run products
Fossil material for composition and morphology
Biological material

The image shows the FEI Quanta 650 Scanning Electron Microscope in the Earth Sciences Department Lab E-Beam Suite.

The image shows the computer system for Thermo Scientific Apreo 2 in Materials Department Laboratory.

The images focuses on the energy-dispersive x-ray spectroscopy detector system. The background includes the rest of the FEI Quanta 650 in the Earth Sciences Department E-Beam Suite

Control panel for image analysis sits on table below the Thermo Scientific Apreo 2 SEM computer system located in the Oxford Materials Department. Live feed from inside SEM and sample analysis are shown on the screens.

The image is focused on the Compact Cold Cathode Gauge of the FEI Quanta 650 SEM located in the E-Beam Suite of the Earth Sciences Department.

The Earth Sciences Department also houses a CAMECA SX-5 FE, an electron beam micro-analyser (EPMA), commonly referred to as an “e-Probe”, that can quantify chemical compositions at the micron scale with typical detection limits of ~100ppm (0.01 wt%). It can perform major, minor, and trace elemental analysis of elements from carbon to uranium on a variety of solid samples. The e-Probe is a non-destructive approach to chemical analysis, though a flat, polished surface is required. Typically, samples are mounted in vacuum-tolerant epoxy resin or conductive bakelite (metal alloys) and polished prior to analyses.