Mössbauer Spectrometer

The study of redox processes and their relation to the evolution of terrestrial bodies is of great interest to the planetary science community.Mössbauer spectroscopy remains the “gold standard” method for Fe3+/Fe2+ determinations in powdered planetary materials such as meteorites, fulgurites, and individual mineral species used for spectral databases.Our Mössbauer spectroscopy facility has acquired roughly 1,800 spectra from 1986-1998, an additional >2,100 spectra from 1998-2000, and more than 6,300 spectra since 2000.

Our Web Research Co.(now See Co.) W100 spectrometer with a Janis closed cycle He cryostat, purchased in 1999, has capabilities that are fairly unique among Mössbauer labs in the U.S. Our use of a closed-cycle He cryostat makes it economical to acquire data at any temperature between 4.5K and room temperature.We routinely run samples with weights of 3-10 mg; for most materials, an optimal sample quantity is roughly 40 mg.The capability to run such small sample amounts makes it possible for us to study experimental run products, small samples that have been hand-picked from rocks and meteorites, and returned samples.

Notable projects in support of NASA efforts have included many studies of mineral separates from meteorites including SNC’s, ongoing work on lunar samples and eucrites, and many analyses in support of Ph.D. theses including work on fulgurites (Abigail Sheffer, ASU), synthetic pyroxenes (Rachel Klima, Brown University), space weathering (Sarah Noble, Brown University), acid weathering products (Nick Tosca, Stony Brook), and bioreduced minerals (Srishti Kashyap, University of Massachusetts) among many others.More than 115 papers have been published in the past 10 years alone that make use of data from this laboratory.