Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS) at Imaging and Chemical Analysis Laboratory (ICAL), MSU-Bozeman
Montana State University, ICAL Website
Sara Zacher (Lab Manager) or Recep Avci (Lab Director)
406 994 4199
ToF-SIMS Time-of-flight secondary ion mass spectrometer
- MODEL: Cameca IonToF IV
- An example of a Cameca IonTof IV ToFSIMS instrument at the University of Oregon
ToF-SIMS is widely used in nano-engineering research on semi-conductors and related microelectronics, polymer, thin film, metallurgy, ceramics, energy, and medical devices. ToF-SIMS has not been widely used in Earth and Environmental Sciences, but applications include documenting thin carbon films on mineral grain boundaries, search for biomarkers in the geologic record, interplanetary dust, evidence of magmatic fluids, and studies of coal macerals.
Backscattered electron image of garnet amphibolite. Note garnet is green; hornblende is light blue.
Carbon map. Note interconnecting network of carbon along hornblende cleavages.
Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a surface-sensitive analytical method that uses a pulsed ion beam (e.g., Ga) to remove molecules from the very outermost atomic monolayers on the surface, producing secondary ions. Three operational modes are available using ToF-SIMS: surface spectrometry, surface imaging and depth profiling. Analytical capabilities of ToF-SIMS include: a) Mass resolution of 0.00x amu. Particles with the same nominal mass (e.g. Si and C2H4, both with amu = 28 ) are easily distinguished from one another because as Mr. Einstein predicted there is a slight mass shift as atoms enter a bound state. b) Mass range of 0-10,000 amu; ions (positive or negative), isotopes, and molecular compounds (including polymers, organic compounds, and up to ~amino acids) can be detected. c) Trace element detection limits in the ppm range. d) Sub-micron imaging to map any mass number of interest. e) Depth profiling capabilities; sequential sputtering of surfaces allow analysis of the chemical stratigraphy on material surfaces (typical sputtering rates are ~100 A/minute). f) Retrospective analysis. Every pixel of a ToF-SIMS map represents a full mass spectrum. This allows an analyst to retrospectively produce maps for any mass of interest, and to interrogate regions of interest (ROI) for their chemical composition via computer processing after the dataset has been instrumentally acquired. Acquired mass data differentiate isolated monomers, simple molecular compounds, and more complex organic compounds with masses ~ 1000 amu.
Particle beam interaction using ToF-SIMS. Incident particles bombard the surface liberating single ions (+/-) and molecular compounds.
Conditions for Use:
Submitted samples will be analyzed on a contract basis (i.e. lab personnel will do the work) Visitors are invited to work in the lab to work with lab personnel Visitors are invited to work in the lab to design and do the work yourself Training Session (short course) is offered
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.
Scheduling is supervised by the lab manager. In general, class demonstrations/projects are scheduled to accommodate academic schedules. External clients (other universities, government agencies, corporate) are scheduled for rapid turn-around of results. All certified users (who take our ~10 hour short courses) are authorized to sign up for instrument use 24/7 at our reservation site: https://www.montana.edu/cpa/apps/ical_tools/index.php . We prefer certified users to design and implement their own experiments, but lab staff are available to assist independent users as needed in experiment design, instrument operation and interpretation of results.
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 usually analyzed "as received". Small samples <1 cm are required and any volatile samples are also avoided due to stability issues in ultrahigh vacuum. Samples are usually "dusted off" with a light sputtering under the Ar beam to clean off any sorbed atmospheric contaminants.
Standard Collections/Lab Blanks:
- 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)