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  1. No Access

    Article

    Preferred Orientation Patterns of Phyllosilicates in Surface Clays

    The alignment of phyllosilicates in clays has received a lot of attention because it is a major cause of seismic anisotropy in the Earth’s crust. Thus far, all attention has been on shales where the orientatio...

    H.-R. Wenk, R. Vasin in Clays and Clay Minerals (2017)

  2. No Access

    Article

    Texture development and slip systems in bridgmanite and bridgmanite + ferropericlase aggregates

    Bridgmanite (Mg,Fe)SiO3 and ferropericlase (Mg,Fe)O are the most abundant phases in the lower mantle and localized regions of the D″ layer just above the core mantle boundary. Seismic anisotropy is observed near ...

    L. Miyagi, H.-R. Wenk in Physics and Chemistry of Minerals (2016)

  3. No Access

    Chapter and Conference Paper

    In Situ TEM Observation of Twinning, Detwinning and Retwinning in Quartz

    Quartz nanopillars were fabricated by focused ion beam technique from a natural crystal. The nanopillars were deformed by in situ compression test in a transmission electron microscope. During loading and unlo...

    E. Tochigi, E. Zepeda, H.-R. Wenk, A. M. Minor in MEMS and Nanotechnology, Volume 5 (2016)

  4. No Access

    Article

    In situ TEM observations of plastic deformation in quartz crystals

    With in situ nanocompression experiments in a transmission electron microscope, we investigated plastic deformation in natural quartz crystals and observed both dislocation plasticity as well as mechanical twi...

    E. Tochigi, E. Zepeda-alarcon, H.-R. Wenk, A. M. Minor in Physics and Chemistry of Minerals (2014)

  5. No Access

    Article

    Crystallographic preferred orientation in wüstite (FeO) through the cubic-to-rhombohedral phase transition

    Magnesiowüstite, (Mg0.08Fe0.88)O, and wüstite, Fe0.94O, were compressed to ~36 GPa at ambient temperature in the diamond anvil cell (DAC) at the Advanced Light Source. X-ray diffraction patterns were taken in sit...

    P. Kaercher, S. Speziale, L. Miyagi… in Physics and Chemistry of Minerals (2012)

  6. No Access

    Article

    Application of Neutron Scattering in Earth Sciences

    The unique properties of neutron interaction with materials have long been applied to the study of geological materials, with Shull and Smart using them in 1949 to determine the antiferromagnetic structure of ...

    H.-R. Wenk in JOM (2012)

  7. No Access

    Article

    Preferred orientations and anisotropy in shales: Callovo-Oxfordian shale (France) and Opalinus Clay (Switzerland)

    Anisotropy in clay-rich sedimentary rocks is receiving increasing attention. Seismic anisotropy is essential in the prospecting for petroleum deposits. Anisotropy of diffusion has become relevant for environme...

    H.-R. Wenk, M. Voltolini, M. Mazurek, L. R. Van Loon, A. Vinsot in Clays and Clay Minerals (2008)

  8. No Access

    Article

    Dauphiné twinning and texture memory in polycrystalline quartz

    Mechanical twinning in polycrystalline quartz was investigated in situ with time-of-flight neutron diffraction and a strain diffractometer. Dauphiné twinning is highly temperature sensitive. It initiates at a ...

    H.-R. Wenk, M. Bortolotti, N. Barton, E. Oliver… in Physics and Chemistry of Minerals (2007)

  9. No Access

    Article

    Microstructure and microtexture of highly cold-rolled commercially pure titanium

    The microstructure and texture evolution of a commercially pure titanium sheet during cold-rolling is investigated in detail by X-ray diffraction and by orientation imaging in the FEG-SEM and in the TEM. The e...

    N. Bozzolo, N. Dewobroto, H. R. Wenk, F. Wagner in Journal of Materials Science (2007)

  10. No Access

    Article

    Basal slip and texture development in calcite: new results from torsion experiments

    The deformation behavior of calcite has been of longstanding interest. Through experiments on single crystals, deformation mechanisms were established such as mechanical twinning on

    D. J. Barber, H.-R. Wenk, J. Gomez-Barreiro… in Physics and Chemistry of Minerals (2007)

  11. No Access

    Article

    In-Situ Observation of Texture Changes during Phase Transformations in Ultra-Low-Carbon Steel

    Texture changes during the α(bcc)-γ(fcc) phase transformation in ultra-low-carbon (ULC) steel were investigated in situ by neutron diffraction, making use of a vacuum furnace. The initial texture is a typical bcc...

    H.-R. Wenk, I. Huensche, Leo Kestens in Metallurgical and Materials Transactions A (2007)

  12. No Access

    Article

    Texture analysis of ancient coins with TOF neutron diffraction

    Two ancient Greek coins were studied by time-of-flight (TOF) neutron diffraction to investigate their authenticity. Diffraction spectra were analyzed with the Rietveld programs GSAS and MAUD for phase proporti...

    Yanxia **e, L. Lutterotti, H. R. Wenk, F. Kovacs in Journal of Materials Science (2004)

  13. No Access

    Article

    Texturing of the Earth's inner core by Maxwell stresses

    Elastic anisotropy in the Earth's inner core has been attributed to a preferred lattice orientation1, which may be acquired during solidification of the inner core2 or developed subsequent to solidification as a ...

    B. A. Buffett, H.-R. Wenk in Nature (2001)

  14. No Access

    Article

    The plastic deformation of iron at pressures of the Earth's inner core

    Soon after the discovery of seismic anisotropy in the Earth's inner core1, it was suggested that crystal alignment attained during deformation might be responsible2. Since then, several other mechanisms have been...

    H.-R. Wenk, S. Matthies, R. J. Hemley, H.-K. Mao, J. Shu in Nature (2000)

  15. No Access

    Article

    Microfibrous quartz varieties: characterization by quantitative X-ray texture analysis and transmission electron microscopy

    Quantitative X-ray texture analysis was used to identify the fiber elongation direction of microfibrous quartz varieties in materials that contain narrow bands of closely spaced, radially divergent spheruliti...

    S. L. Cady, H.-R. Wenk, M. Sintubin in Contributions to Mineralogy and Petrology (1998)

  16. No Access

    Chapter

    Electron, Acoustic, and Tunneling Microscopy of Minerals

    There are basically two distinct types of electron microscope. The transmission electron microscope (TEM) is the analog of the transmission hght microscope and provides information about the internal structure...

    H.-R. Wenk, A. C. McLaren, G. M. Pennock… in Methods and Instrumentations: Results and … (1995)

  17. No Access

    Article

    3-D Imaging of Crystals at Atomic Resolution

    Electron crystallography has now been used to investigate the structures of inorganic materials in three dimensions. As a test of the method, amplitudes and phases of structure factors were obtained experiment...

    M. A. O’keefe, K. H. Downing, H.-R. Wenk, Hu Meisheng in MRS Online Proceedings Library (1994)

  18. No Access

    Chapter

    Preferred Orientation and Velocity Anisotropy in Marine Clay-Bearing Calcareous Sediments

    In order to better understand the role of preferred orientation of calcite in the compressional velocity (V p ) anisotropy of calcareous marine sediments, ultras...

    David K. O’Brien, Murli H. Manghnani, Jane S. Tribble, H.-R. Wenk in Carbonate Microfabrics (1993)

  19. No Access

    Article

    Textures of laser ablated superconducting thin films of YBa2Cu3O7−δ as a function of deposition temperature

    The preferred orientation of a series of laser deposited superconducting thin films of YBa2Cu3O7−δ on LaAlO3 substrate has been examined. X-ray measurements (pole figures, χ-scans, ω-scans, rocking curves) reveal...

    F. Heidelbach, H- R. Wenk, R. E. Muenchausen, S. Foltyn… in Journal of Materials Research (1992)

  20. No Access

    Article

    Superstructures in ankerite and calcite

    Two rhombohedral carbonates, ferroan dolomite (ankerite) and magnesian calcite from lower Jurassic ammonites, have been studied by transmission electron microscopy. The samples show small domains with the morp...

    H.-R. Wenk, Hu Meisheng, T. Lindsey, J. W. Morris Jr. in Physics and Chemistry of Minerals (1991)

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