Auger Electron Spectroscopy System Integrated with EDS and EBSD at the Imaging and Chemical Analysis Laboratory (ICAL), MSU-Bozeman
Montana State University-Bozeman
Auger Electron Spectroscopy System Integrated with EDS and EBSD
- Field Emission SEM scanning electron microscope--for high resolution imaging down to 5 nanometers
- AES Auger Electron Spectroscopy (or SAM Scanning Auger Microscopy)--for surface analysis of all elements of Z>3 (Li), and surface elemental mapping
- EDS energy dispersive spectrometer--for "bulk" compositional analysis of elements; X-ray elemental mapping
- EBSD detector for in situ phase identification using electron diffraction and determination of crystallographic orientation.
This Phi 710 NanoAuger Probe is a unique analytical system that includes: 1) Field Emission SEM imaging for spatial resolution down to 5 nanometeers; 2) AES detector for surficial compositional analysis for atomic monolayers on surfaces, with detection of light elements down to Li; 3) Ar-beam ion gun for "dusting off" surfaces of environmental contaminants and depth profiling capabilities; 4) EDS detector for "bulk" compositional analysis and X-ray elemental mapping of materials, and 5) EBSD detector for phase identification using electron diffraction and determination of crystallographic orientation. These numerous analytical methods can be used in near-real-time to fully characterize in situ the identity, crystal structure and orientation, bulk composition, and surface composition of sub-micron to micron particles. Charge compensation methods are used to analyze insulating materials because conducting coats cannot be applied to AES samples.
Auger Electron Spectroscopy (AES) is a surface sensitive method used to analyze the composition of one or a few atomic layers (~1 nanometer) on material surfaces. All elements of Z>3 (Li) can be detected. Semi-quantitative analyses are obtained using published elemental sensitivity factors. Depth profiles of chemical stratigraphy on material surfaces is obtained using an Ar ion sputter gun. Full spectrum surveys are obtained to determine the inventory of elements on a material surface, and "multiplex" routines are used to scan specific energy windows to focus on specific elements. Micron-scale maps can be obtained to show the distribution of elements on material surfaces. The AES instrument at ICAL is built on a field emission SEM for high resolution imaging, and is also equpped with EDS and EBSD detectors. So near real-time data can be obtained in situ on the same spot for nano-scale morphology, bulk composition, surface composition, atomic structure (to identify the phase) and crystallographic orientation.
- Study of surface mediated reactions such as sorption, catalysis, dissolution/preciptation products, REDOX reactions
- Analysis of thin films and surface coatings
- Imaging (size, shape, morphology)
- Crystallographic orientation
- Distribution in matrix (disseminated, aggregated...)
- Textural relations (intergrowths, overgrowths, epitaxial...)
AES is widely used in research in
- Energy (generation, storage, transfer)
- Earth and Environmental Sciences (applications are increasing as charge compensation methods are improved).
Conditions for Use:
As a regional user facility, ICAL encourages users to acquire training through our Short Courses so that the design and implementation of experiments is done to meet specific user-defined research objectives. Collaboration with ICAL staff is encouraged. Submitted samples can also be analyzed on a contract basis (i.e. lab personnel will do the work). ICAL is also available to do preliminary "proof-of-concept", exploratory experiments, including optimazation of instruments to address the defined tasks, data acquistion, and data interpretation to help support future funding and collaboration opportunities.
Contact the lab manager for details about user fees. In general, user fees are applied only to actual beam time for instrument use and staff time.
ICAL seeks to accommodate all users who rely on high-quality, rapid turn-around results for both academic research and research and development projects for industrial partners. The lab manager helps coordinate instrument access by: a) researchers with funded research projects; b) collaborations with academic colleagues; c) contract work with industrial partners, and d) education and outreach activities (class demonstrations, class projects, independent study and thesis research projects, etc.). ICAL is a node of the National Nanotechnology Coordinated Infrastructure program, and our mission is to extend use of these instruments to support research across the STEM disciplines in academic and corporate research. Some limited funds are available through the NNCI/MONT NSF award to support pilot research projects. Please visit https://nano.montana.edu/ for details.
Remote operation is not directly possible for any of the ICAL instruments. But in response to the COVID lockdowns, we have implemented use of real-time video delivery to allow external users to observe analysis of their samples and to provide for direct interaction and decision-making as the experiments proceed.
Samples are typically analyzed "as received". The AES operates under Ultra High Vacuum (UHV) so volatile materials should be avoided. Samples are commonly mounted on a conducting material such as indium, a Si wafer, or TEM-style Cu grid. Samples are typically exposed to a gentle Ar beam application to remove sorbed environmental layers.
Standard Collections/Lab Blanks:
Standardization for AES analysis is difficult and not commonly done.
AES data collection provides retrospective analysis as every pixel of the image contains the full Auger spectrum.
Class demonstrations are available for undergraduates Class demonstrations are available for K-12 Undergraduate student research projects are invited Graduate student research projects are invited Tutorials and other educational materials related to the lab are available ICAL routinely offers class demonstrations and supports course projects across the STEM disciplines. We encourage interested users to take our 10 hour short courses in the operation of each instrument to become independent users of this facility as part of our professional training program.
Support provided by:
The ICAL facility is partly funded by the NSF National Nanotechnology Coordinated Infrastructure Program, award #2025391, Montana Nanotechnology Facility (MONT). The AES system was supported with funds from the Murdock charitable Trust and funds from the Vice President for Research, Montana State University.