November 3-5, 2005

Hightlights from the COMPRES-Sponsored Workshop on Synchrotron Infrared Spectroscopy for High Pressure Geoscience and Planetary Science

In recent years, infrared (IR) microscopy and spectroscopy have greatly benefited from new synchrotron techniques. New infrared synchrotron radiation sources provide a tremendous improvement in flux on a sample, with well-collimated beams from far- to near-IR that give high spatial resolution with unmatched signal-to-noise. This has opened up new scientific directions in a range of fields, including physics, biology, chemistry, materials science, high-technology, and forensics. One of the most exciting areas, however, is high-pressure geoscience and planetary science. High-pressure synchrotron IR spectromicroscopy is an ideal coupling of the diamond anvil cell device and synchrotron IR radiation. In addition, the technique serves as a useful, if not unique, tool to study minerals quenched from high pressures and temperatures, and natural samples (including natural high-pressure assemblages) at ambient conditions.

Participants of the Workshop on Synchrotron Infrared Spectroscopy for High Pressure Geoscience and Planetary Science.

Sponsored by COMPRES (the Consortium for Materials Properties Research in Earth Sciences) and the National Synchrotron Light Source (NSLS), the workshop on Synchrotron Infrared Spectroscopy for High Pressure Geoscience and Planetary Science was held at the NSLS on November 3-5, 2005. The conveners were Zhenxian Liu and Russell J. Hemley (Geophysical Laboratory, Carnegie Institution of Washington). Thanks to the members of the COMPRES Executive Committee and the NSLS staff for suggesting, promoting, and supporting this IR workshop. It was a great success in terms of the excellence of the lectures, its broad attendance that included many new potential users and student participation, its extensive program, and plenty of hands-on experience for new users. More than 50 attendees took part (this was the maximum allowed by the budget and the size of the lecture room).

The workshop consisted of five sessions designed to accommodate the broad spectrum of attendees, ranging from experts to new users. The Friday morning session was directed toward attendees who were new to the modern IR spectroscopy techniques used in this field, but, for experienced users, it was also a very useful review of the fundamentals and new developments. Q. Williams (University of California at Santa Cruz) gave a thorough overview on IR spectroscopy (and FT techniques in general) and its applications in the Earth sciences. G. Rossman (California Institute of Technology) gave a talk on hydrous components in nominally anhydrous minerals, which was crucially important for users who are interested in the calibration of the water content in minerals. A. Hofmeister (Washington University in St. Louis) discussed the high-pressure far-IR spectroscopy of mantle candidate minerals that are worth pursuing with the synchrotron technique. Finally, J. Tse (University of Saskatchewan, Canada) described theoretical methods for vibrational spectroscopy and many other applications.

The Friday afternoon session was started by L. Carr (NSLS). He gave a very comprehensive talk on Fourier transform spectroscopy techniques using the synchrotron infrared source as well as an overview of the IR programs at the NSLS. There were seven additional speakers (A. Goncharov, V. Struzhkin, and S. Jacobsen, Geophysical Laboratory; D. Klug, Canadian Research Council; H. Scott, Indiana University at South Bend; G. Lager, University of Louisville; and Y. Lee, Brookhaven National Laboratory) who discussed different topics related to the work they have done at NSLS beamline U2A. These talks not only addressed a broad range of problems in the Earth and planetary sciences but also reflected new techniques developed at U2A in past years.

The third session, held Saturday morning, focused on imaging techniques combined with synchrotron sources. L. Miller (NSLS) gave an extensive overview of chemical imaging at high spatial resolution using a synchrotron infrared microscope. Other speakers (L. Wang, Stony Brook University; L. Dobrzhinetskaya, University of California at Riverside; M. Koch-Müller, GeoForschungsZentrum Potsdam, Germany; and S. Clark, Advanced Light Source) gave talks featuring the applications of imaging techniques as well as high-pressure IR studies at other synchrotron sources. The facility tour and hands-on session on Saturday afternoon attracted more than 30 people. At the IR beamline, new users received detailed information on the beamline facility and its capabilities, as well as first-hand experience on how to perform high-pressure IR experiments from beginning to end.

The last session, for student/post-doc experiments at U2A, started right after the workshop. Two students and one post-doc submitted their research proposals and one day of beamtime was allocated per proposal. This new session offered not only a great opportunity to learn how to use the synchrotron IR facility but also a chance to collect valuable data for their research projects. The experiments went very well and the IR data they obtained are very interesting and are publishable in scientific journals.

RELATED LINKS: Workshop Website

ARTICLE BY: Zhenxian Liu