|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Characterization of Materials through High Resolution Coherent Imaging
||Soft-X-ray Ptychographic Imaging of Shale
||Namhey Lee, Peter Nico, David Shapiro, Manika Prasad, Timothy Kneafsey, Benjamin Gilbert
|On-Site Speaker (Planned)
Shales are important sedimentary rock formations for energy resources and geologic storage of waste materials due to their very low permeability. Soft-X-ray ptychography provides a new approach for imaging the pore structures in shale that is complementary to electron microscopy, helium ion microscopy and scanning transmission X-ray microscopy. Ptychography acquires the complex refractive index of the sample that is better suited to low-density materials such as kerogen. We performed non-resonant soft-X-ray ptychographic imaging of carbonate rich (Niobara) and organic rich (Bakken) shale rocks thinned to 0.5 µm using focused ion beam milling. In all samples, two-dimensional (2D) projection images revealed complex internal structure with 5-nm features resolved. In organic-rich shale, 2D transmission images reveal nanoscale porosity consistent with HIM images of fractured shale. Wavy lamellar structures within organic components are likely clay minerals. However, determination of nanoscale pore structure is affected by statistical noise in the diffraction data.
||Planned: Supplemental Proceedings volume