Hydrothermal diamond anvil cell for XAFS studies of first-row transition elements in aqueous solution up to supercritical conditions

William A. Bassett:  Department of Geological Sciences, Cornell University, Ithaca, NY 14853,
    U.S.A.
Alan J. Anderson:  Department of Geology, St. Francis Xavier University, P.O. Box 5000,
    Antigonish, Nova Scotia B2G 2W5, Canada
Robert A. Mayanovic:  Department of Physics and Astronomy, Southwest Missouri State
    University, Springfield, MO 65804, U.S.A.
I-Ming Chou:  MS 955, U.S. Geological Survey, Reston, VA 20192, U.S.A.

ABSTRACT

A hydrothermal diamond anvil cell (HDAC) has been modified by drilling holes with a laser to within 150 µm of the anvil face to minimize the loss of X-rays due to absorption and scatter by diamond. This modification enables acquisition of K-edge X-ray absorption fine structure (XAFS) spectra from first row transition metal ions in aqueous solutions at temperatures ranging from 25 to 660°C and pressures up to 800 MPa. These pressure-temperature conditions are more than sufficient for carrying out experimental measurements that can provide data valuable in the interpretation of fluid inclusions in minerals found in ore-forming hydrothermal systems as well as other important lithospheric processes involving water.