Seminar Announcement: Extending Synchrotron X-ray Microscopy to the Laboratory: Applications for Materials and Life Sciences in 3- and 4-Dimensions Arno P. Merkle1, Ph.D. 1 Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA USA arno.merkle@zeiss Wednesday, September 18’th 2013 2:00 pm – 3:00 pm AMRL Conference Room, Research Park (Please Note: Refreshments will be provided after the seminar) 3D x-ray microscopy has emerged as a powerful imaging technique that obtains information from a range of materials under a variety of conditions and environments. Recently, laboratory-based x-ray sources have been coupled with high resolution x-ray focusing and detection optics from synchrotron-based systems to acquire tomographic datasets with resolution down to 50 nm [1]. This represents an improvement of at least one order of magnitude in true spatial resolution beyond the limits of conventional laboratory computed tomography (CT) techniques. This talk will explore both the details of the optics involved (FIG 1) in such a laboratory-based x-ray microscopes but also several important applications examples of how x-ray tomography has been used as a complement to electron and optical microscopy investigations. Observing the evolution of microstructure on the identical region of a single sample can rapidly benefit materials modeling techniques, by avoiding the requirement to extrapolate based on statistical samplings from a large number of like specimens. This is largely a unique capacity of x-ray tomography and several examples of in situ and ‘4D’ experiments will be presented, including crack propagation in ceramics, porosity and permeability characterization, deformation of polymer foams under load and the evolution of defects in battery anode materials in Lithium ion batteries [2](FIG 2). Soft materials, ranging from polymers to biological tissue, consistently pose challenges in generating contrast by several techniques, x-ray absorption included. We demonstrate the application of both phase propagation and Zernike phase contrast techniques on such materials, including polymer electrolyte fuel cells [3] and superconducting materials. Finally, the workflow employing 3D & 4D x-ray microscopy as a complementary step prior to complementary high-resolution 2D and 3D techniques will be discussed. References [1] A. Tkachuk, et. al., X-ray computed tomography in Zernike phase contrast mode at 8 keV with 50-nm resolution using Cu rotating anode X-ray source Z. Kristallogr. 222 (2007) 650–655 [2] P.Shearing, et. al., In situ x-ray spectroscopy and imaging of battery materials. ECS Interface, 20 3 (2011) p.43 [3] W.K. Epting, J. Gelb, S. Litster Resolving the Three-Dimensional Microstructure of Polymer Electrolyte Fuel Cell Electrodes using Nanometer-Scale X-ray Computed Tomography Advanced Functional Materials (2011) FIG. 1. X-ray optical schematic of the Xradia UltraXRM-L200, achieving 50 nm spatial resolution with an 8kV laboratory source. FIG. 2. (left) 3D reconstruction of a battery electrode material, acquired with the laboratory-based UltraXRM-L200 x-ray microscope. (right) 3D view of a polyamide sample, exhibiting silica platelets. The quantity and distribution of particles in this composite material is studied using XRM techniques at the nanoscale. Speaker Bio: Arno Merkle is responsible for the academic market segment of the Carl Zeiss X-ray Microscopy division. Prior to joining Carl Zeiss X-ray Microscopy (formerly Xradia, Inc.), Arno was part of the product management group for electron and helium ion microscopy for ZEISS, based outside of Boston. He received his Ph.D. in Materials Science and Engineering from Northwestern University in 2007 and has a background in a variety of high-resolution microscopy techniques.
Posted on: Mon, 09 Sep 2013 15:31:20 +0000
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