Community Facility Support: The Arizona State University SIMS Laboratories

Arizona State University, Scottsdale AZ

Investigators

Abstract

This award continues support of the Arizona State University Community Secondary Ion Mass Spectrometer (SIMS) Facility that will provide NSF-researchers in Earth Sciences access to two complex analytical instruments that allow them to analyze very small areas in natural and synthetic materials. The NanoSIMS can detect and quantify signals from a spot as small as 50 nanometers across. This is ~1000 times less than the width of a human hair. The 6f SIMS instrument analyzes larger areas (a few micrometers across), but can achieve sub-micron resolution in depth. Both instruments are expensive, require major efforts to maintain, and can be challenging to use. The funds support ASU specialists who work with visitors and help them design their experiments and select instrument protocols to get the best possible analyses from their samples. Visitors are taught how to operate the instruments for their particular problem, instructed in the basic principles of SIMS, and encouraged to describe new questions so that the facility specialists may develop appropriate, novel analysis techniques using these instruments. The SIMS technique has multiple applications in Earth and Space Sciences, nuclear non-proliferation, and the semiconductor/materials science fields. Thus, the knowledge gained by visitors and Facility-supported students in the past has helped them obtain employment in SIMS labs in industry, academia, and national laboratories. During the past funding cycle (September 2014 through May 2018), the facility helped a diverse group of visitors obtain the best possible trace element and isotopic microanalyses. In the new funding period the facility will continue this role in the US geochemical community, and add functionality through development of new analytical techniques, improving quantification and infrastructure (standards), and enhancing educational approaches for new visitors (training). The existing facility contains two Cameca instruments (IMS 6f and NanoSIMS). The IMS 6f has excellent specifications for sample chamber vacuum (enabling trace H, and C analyses and isotope measurements for trace H), transmission, mass resolution and lateral and depth resolution. It is well-suited for precise isotope ratio measurements and trace element analyses in small (several micrometer) areas and for in-depth profiling of trace element distributions with few-nanometer resolution. The NanoSIMS has extremely high lateral resolution coupled with high secondary ion transmission at high mass resolving power. It is a good match for a wide range of NSF EAR-supported research and is the only NanoSIMS in the US that acts as an open facility. Arizona State University has been a leader in SIMS research and development for over 30 years and is known for cross-disciplinary collaborations. The renewal of this facility support will allow ASU to continue sharing expertise with a broad spectrum of earth scientists while continuing to improve existing and develop new analytical techniques. The ASU SIMS labs participate in open houses for the general public, conduct a workshop once a year (mostly for graduate students), and create training guides for those interested in learning more details about this rich analysis technique. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.