A. Herring, OSU, uses tomography at 13 BMD to quantify pore scale trapping and to analyze how mechanisms affect the efficiency of capillary trapping of CO2 in saline aquifers.
Tomography at 13 BMD
A team utilizing GSECARS bealines has identified a weird form of crystallized water known as ice VII, suggesting that this material may circulate more freely at some depths within Earth than previously thought. Pockets of water may lay deep below Earth’s surface
Work at GSECARS discovers water deep below Earth’s surface
X-ray diffraction is the most powerful technique for crystal structure determination. From left to right, patterns from a single crystal, polychrystalline, nano-cyrstalline and amorphous crystals.
X-ray diffraction patterns from a diamond anvil cell.
The HPXTM module helps researchers study the texture change of their sample under extreme pressure and temperature conditions by collecting in-situ HP/HT 3D x-ray tomographic images.
High Pressure X-ray Tomographic Microscopy Module sitting outside of the 250 ton press in 13 BMD.
GSECARS hosts experiments at 13 IDE for high school students in the Exemplary Student Research Program (ESRP) representing local area high schools. GSECARS Outreach
GSECARS Outreach
GSECARS is a national user facility
for frontier research in the earth sciences using synchrotron radiation at the
Advanced Photon Source, Argonne National Laboratory.
GSECARS provides earth scientists with access to the high-brilliance hard x-rays from this third-generation synchrotron light source. All principal synchrotron-based analytical techniques in demand by earth scientists are being brought to bear on earth science problems:
- High-pressure/high-temperature crystallography and spectroscopy using the diamond anvil cell
- High-pressure/high-temperature crystallography and imaging using the large-volume press
- Powder, single crystal and interface diffraction
- Inelastic x-ray scattering
- X-ray absorption fine structure spectroscopy
- X-ray fluorescence microprobe analysis
- Microtomograph
► Science Highlights
► Work done at 13 BMC has provided evidence for using Fe-(oxyhydr) oxides as potential treatment substrates to remediate Pb contaminated soils.
The structure above has been oriented to highlight the geometric relationship between Pb complex and the associated anchored Fe octahedra.
Abstract
A structural study of the surface complexation of Pb(II) on the (1102) surface of hematite was undertaken using crystal truncation rod (CTR) X-ray diffraction measurements under in situ conditions. The sorbed Pb was found to form inner sphere (IS) complexes at two types of edge-sharing sites on the half layer termination of the hematite (1102) surface. The best fit model contains Pb in distorted trigonal pyramids with an average Pb_O bond length of 2.27(4) Å and two characteristic Pb-Fe distances of 3.19(1) Å and 3.59(1) Å. In addition, a site coverage model was developed to simulate coverage as a function of sorbate-sorbate distance. The simulation results suggest a plausible Pb-Pb distance of 5.42 Å, which is slightly larger than the diameter of Pb’s first hydration shell. This relates the best fit surface coverage of 0.59(4) Pb per unit cell at monolayer saturation to steric constraints as well as electrostatic repulsion imposed by the hydrated Pb complex. Based on the structural results we propose a stoichiometry of the surface complexation reaction of Pb(II) on the hematite (102) surface and use bond valence analysis to assign the protonation schemes of surface oxygens. Surface reaction stoichiometry suggests that the proton release in the course of surface complexation occurs from the Pb-bound surface O atoms at pH 5.5.
C. Qiu, F. Majs, P.J. Eng, J.E. Stubbs, T.A. Douglas, M. Schmidt, T. Trainor, "In situ structural study of the surface complexation of lead(II) on the chemically mechanically polished hematite (1102) surface", J. Colloid and Interface Science,(2018) Vol. 524, pp. 65-75, DOI : 10.1016/j.jcis.2018.04.005
► Inclusions of ice-VII found in diamonds from the mantle transition zone.
National Science Foundation "News From the Field " Highlight
Argonne National Laboratory Science Highlight
UChicago News
An international team of scientists have discovered the presence of a high pressure phase of water preserved as inclusions in diamonds which formed in the Earth's mantle at depths exceeding 410 km. Using a combination of high resolution synchrotron techniques including X-ray diffraction and fluorescence at the Advanced Photon Source (GSECARS sector 13) and infrared spectroscopy at the Advanced Light Source and at CalTech, the discovery of ice-VII in these diamonds provides potential evidence for the presence of aqueous fluids in the Earth's mantle. Ice-VII is a high pressure polymorph of water-ice and has been recently approved as a mineral by the International Mineralogical Association based on X-ray diffraction data collected at GSECARS. Earth scientists have long debated how much water may be preserved in the regions of the mantle from where these diamonds are believed to have formed, the transition zone and at lower mantle boundary. These inclusions are believed to be residues of aqueous fluids present in the mantle when the diamonds formed, at pressures as high as 24 GPa, with the ice-VII phase crystallizing within the diamond upon ascent. The included ice-VII preserves the high pressures at which the fluids were included and represent the highest pressure of a molecular solid directly observed in nature. This finding has important implications for our understanding of how water and heat-generating elements such as K, U, Th, which have increased solubility in aqueous fluids, may be recycled in the deep Earth, for example though subduction zone processes.
Above (left to right) : Vitali Prakapenka, Tony Lanzirotti, Matt Newville, Eran Greenberg, Dongzhou Zhang.
O. Tschauner, S. Huang, E. Greenberg, V.B. Prakapenka, C. Ma, G.R. Rossman, A.H. Shen, D. Zhang, M. Newville, A. Lanzirotti, K. Tait, “Ice-VII inclusions in diamonds: Evidence for aqueous fluid in Earth’s deep mantle,” Science 359, 1136 (9 March 2018). DOI: 10.1126/science.aao3030
Happenings
Mike Wenz, Lead Systems Engineer for the Optical Telescope Assembly of the Hubble Space Telescope, presented a talk title "A Behind the Scenes Look at the Hubble Space Telescope Operations". Hosted by GSECARS, Mike talked about the people and stories involved in keeping the Hubble humming for the last 28 years.
As part of ANL's Exemplary Student Research Program, GSECARS hosted high school students from Community High School District 99 South High School at 13 IDE. The results from their project, "Connection Between Chlorosis in Birch Trees and Nutrient Deficiency in Adjacent Soil" will be presented in a poster at the APS User Meeting in May.
GSECARS also hosted an ESRP group from Glenbard East High School. Their project was titled "The characterization of metal concentration and distribution in lichens with varying tolerance to air pollution."
Chicago Tribune article
GSECARS welcomes Postdoctoral Scholar Dr. Tim Officer from The University of Western Ontario. He will be working with Dr. Yanbin Wang and the GSECARS multi-anvil press program.
Upcoming Events
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News
Imaging in 3D under pressure: a decade of high-pressure X-ray microtomography development at GSECARS
The high-pressure X-ray microtomography (HPXMT) apparatus has been operating at the GeoSoilEnviroCARS (GSECARS) bending magnet beamline at the Advanced Photon Source since 2005. By combining the powerful synchrotron X-ray source and fast switching between white (for X-ray diffraction) and monochromatic (for absorption imaging) modes, this technique provides the high-pressure community with a unique opportunity to image the three-dimensional volume, texture, and microstructure of materials under high pressure and temperature.
NEON Tours Sector 13
GSECARS beamline scientist Tony Lanzirotti gives a tour to earth scientists and geologists from the NSF funded National Ecological Observatory Network (NEON). Tony described how synchrotron facilities can be used to help address geological and environmental questions and problems.
Inspiring the next generation of STEM professionals
The US Dept of Energy, ANL Department of Educational Programs and the Interdisciplinary Consortium for Research and Education and Access in Science and Engineering (INCREASE) organization held a workshop to assist researchers at historically black colleges and universities become acquainted with resources available at DOE national laboratories.
New / updated Map of Argonne available.