ADVANCED APPLICATIONS OF SYNCHROTRON RADIATION IN CLAY SCIENCE

Transcription

1 CMS WORKSHOP LECTURES Volume 19 ADVANCED APPLICATIONS OF SYNCHROTRON RADIATION IN CLAY SCIENCE THE CLAY MINERALS SOCIETY Joseph W. Stucki, Series Editor and Editor in Chief University of Illinois Urbana, IL , USA Glenn A. Waychunas, Volume Editor Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkley, CA 94720, USA

2 Contents Chapter 1. Introduction to synchrotron radiation...1 by GLENN A. WAYCHUNAS 1. X-ray sources short history Vacuum-tube high-voltage sources First-generation synchrotrons and spectrum Wigglers, undulators, and their spectrum Beam parameters Beam brightness and flux Polarization Beam coherency Pulse structure and modes of operation New lattices and FELs (LCLS) Lattices FELs Synchrotron operation considerations Injection Long-term beam stability Important beamline elements Monochromators and mirrors Zone-plate optics Types of experiments (and capabilities) X-ray scattering Powder diffraction (high resolution) Diffuse scattering from poorly crystalline materials, PDF measurements Single-crystal diffraction (small size) Small-angle X-ray scattering (SAXS) (flux and brilliance) Grazing Incidence diffraction and reflectivity (brilliance) X-ray spectroscopy X-ray absorption spectroscopy X-ray microprobe (X-ray emission) Grazing-incidence X-ray fluorescence and X-ray standing wave approaches X-ray spectromicroscopy and nanoprobe Imaging modes Phase contrast X-ray tomography Sources in the US and access The US DOE sources User support (scientists and technologists) Choosing beamlines for experiments... 29

3 IX Acknowledgements...30 References...31 Chapter 2. Synchrotron powder diffraction methods and refinement techniques...33 by JOHN B. PARISE, WILLIAM R. WOERNER and REINHARD B. NEDER 1. Introduction and historical perspective Coherent elastic scattering Small-angle scattering Time-resolved SAS WAXS from geo-nanoparticles Prospects for whole nanoparticle refinement Sample environments Versatile high-temperature sample stages Cells for studies of fluid solid interactions Acoustic levitation Prospects for in situ and time-resolved studies...57 Acknowledgements...60 References...60 Chapter 3. Atomic-scale structure of substantially disordered minerals by high-energy X-ray diffraction and atomic pair distribution function analysis...69 by VALERI PETKOV 1. Introduction Principles of the atomic PDF method Practical aspects of high-energy XRD aimed at atomic PDF Analysis Source of X-ray radiation XRD data statistics and collection time Experimental set-up (Q-space) resolution Background scattering treatment Sample-related unwanted scattering High-energy XRD data processing into atomic PDFs Structural information that can be extracted from atomic PDFs Conclusions...86 Acknowledgements...86 References...86

4 X Chapter 4. Total scattering studies of natural and synthetic ferrihydrite...89 by F. MARC MICHEL 1. Introduction Common occurrences and importance of ferrihydrite Total scattering and the pair distribution function Total scattering methodology The pair distribution function Other terms and concepts Coherent scattering domain size Short-, intermediate-, and long-range order Extracting information from the PDF: Real-space fitting Studies of pure synthetic ferrihydrite Laboratory XRD-based scattering Synchrotron total scattering Laboratory ferrihydrite Ferrihydrite transformations Ferritin-derived ferrihydrite Neutron total scattering Studies of impure synthetic ferrihydrite Mixed Cr x Fe 1 x -(oxy)hydroxides Aluminous ferrihydrite Fe 3þ oxide/silica co-precipitates Arsenious ferrihydrite Arsenate-sorbed ferrihydrite Recent studies and new data for natural ferrihydrite Summary and future work Acknowledgements References Chapter 5. Introduction to computed microtomography and applications in Earth science by MARK L. RIVERS 1. Introduction to computed tomography Overview Microtomography Laboratory X-ray sources Synchrotron X-ray sources Detectors Computers Absorption tomography X-ray energy and sample size Data collection

5 XI 2.3. Data normalization Sinograms Reconstruction Spatial resolution Source size Sample and detector size Visible-light diffraction limit Scintillator limits Rotation stage limits Contrast resolution Differential absorption tomography Phase-constrast tomography Fluorescence tomography Diffraction tomography Applications of tomography in Earth sciences Fluids in porous media Soils Other applications Acknowledgments References Chapter 6. X-ray absorption fine-structure spectroscopy by MATTHEW NEWVILLE 1. Introduction X-ray absorption and fluorescence A simple theoretical description of XAFS The EXAFS equation XAFS measurements: transmission and fluorescence Transmission XAFS measurements Fluorescence XAFS measurements Dead time Complicated XAFS data reduction Pre-edge subtraction and normalization Background subtraction EXAFS Fourier transforms XAFS data modeling Running and using FEFF for EXAFS calculations First-shell fitting Second-shell fitting Interpretation of XANES References...200

6 XII Chapter 7. Application of hard X-ray microprobe methods to clay-rich materials by ANTONIO LANZIROTTI 1. Introduction Overview of instrumentation X-ray fluorescence Micro-focused X-ray absorption spectroscopy Micro-focused X-ray diffraction Examples Characterizing geosynthetic clay liners Uranium speciation in contaminated Hanford sediments Nickel sequestration in soil ferromanganese nodules Direct visualization of oriented mesostructures in clay gels Strontium speciation during reaction of kaolinite with simulated tank-waste leachate Acknowledgements References Chapter 8. Applications of scanning transmission X-ray microscopy in studying clays and their chemical interactions by SATISH C.B. MYNENI, BHOOPESH MISHRA, MICHAEL B. HAY 1. Introduction Scanning transmission X-ray microscopy: introduction and instrumentation details Detection limits Imaging of samples Limitations of STXM Applications of STXM in studies of clay minerals Detection of clay minerals using STXM Structural evaluation of clay minerals using STXM and Al-XANES Sorption of Al on mineral surfaces and neoformation of clays Case studies of STXM on inorganic colloids STXM studies of inorganic colloids and biominerals STXM studies on organic colloids Mapping and detecting organic colloids using STXM STXM studies on the functional group composition of organic molecules in colloids STXM studies on the chemical characteristics of biofilms and bacterial cell membranes

7 XIII 5.4. Limitations of STXM for organic molecule studies Distribution of metals in bacterial and planktonic suspensions Summary and future directions Acknowledgements References...258