The nature of the atomic structure of many non-crystalline materials remains a long-standing open question. We use X-ray scattering to model electron images of amorphous materials, where the analogue 'atoms' consist of 1 μm diameter glass beads. The beads form a substantially random close-packed structure, but are partially ordered in places. X-ray ptycho-tomography reveals the exact position of the beads in 3D and so can be used to compare the modelled electron image with full knowledge of the underlying real structure. Using this, we repeat an experiment reported by Archie Howie and colleagues in 1978 that sought to test for real structure in bright-field electron images of amorphous materials; we demonstrate the validity of the technique, at least in the case of the resolution of the microscopes available at that time and the first Born approximation. We also illustrate how extremely demanding it would have been to infer 3D structure of amorphous material from pairs of stereoscopic images obtained with the same experimental kit: an approach that Archie proposed in the 1970s. We briefly discuss the possibility of using electron ptycho-tomography to solve the amorphous structure problem.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ultramic.2019.02.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nanoscale imaging of Fe-rich inclusions in single-crystal zircon using X-ray ptycho-tomography.
Sci Rep
March 2024
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK.
We apply X-ray ptycho-tomography to perform high-resolution, non-destructive, three-dimensional (3D) imaging of Fe-rich inclusions in paleomagnetically relevant materials (zircon single crystals from the Bishop Tuff ignimbrite). Correlative imaging using quantum diamond magnetic microscopy combined with X-ray fluorescence mapping was used to locate regions containing potential ferromagnetic remanence carriers. Ptycho-tomographic reconstructions with voxel sizes 85 nm and 21 nm were achievable across a field-of-view > 80 µm; voxel sizes as small as 5 nm were achievable over a limited field-of-view using local ptycho-tomography.
View Article and Find Full Text PDFDeep learning enables nanoscale X-ray 3D imaging with limited data.
Light Sci Appl
June 2023
National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA.
Deep neural network can greatly improve tomography reconstruction with limited data. A recent effort of combining ptycho-tomography model with the 3D U-net demonstrated a significant reduction in both the number of projections and computation time, and showed its potential for integrated circuit imaging that requires high-resolution and fast measurement speed.
View Article and Find Full Text PDFAttentional Ptycho-Tomography (APT) for three-dimensional nanoscale X-ray imaging with minimal data acquisition and computation time.
Light Sci Appl
May 2023
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Noninvasive X-ray imaging of nanoscale three-dimensional objects, such as integrated circuits (ICs), generally requires two types of scanning: ptychographic, which is translational and returns estimates of the complex electromagnetic field through the IC; combined with a tomographic scan, which collects these complex field projections from multiple angles. Here, we present Attentional Ptycho-Tomography (APT), an approach to drastically reduce the amount of angular scanning, and thus the total acquisition time. APT is machine learning-based, utilizing axial self-Attention for Ptycho-Tomographic reconstruction.
View Article and Find Full Text PDFThree-dimensional topological magnetic monopoles and their interactions in a ferromagnetic meta-lattice.
Nat Nanotechnol
March 2023
Department of Physics & Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.
Topological magnetic monopoles (TMMs), also known as hedgehogs or Bloch points, are three-dimensional (3D) non-local spin textures that are robust to thermal and quantum fluctuations due to the topology protection. Although TMMs have been observed in skyrmion lattices, spinor Bose-Einstein condensates, chiral magnets, vortex rings and vortex cores, it has been difficult to directly measure the 3D magnetization vector field of TMMs and probe their interactions at the nanoscale. Here we report the creation of 138 stable TMMs at the specific sites of a ferromagnetic meta-lattice at room temperature.
View Article and Find Full Text PDFAn X-ray ptycho-tomography model of `Seeing order in ``amorphous'' materials'.
Ultramicroscopy
August 2019
Department of Electronics and Electrical Engineering, University of Sheffield, North Campus, Broad Lane, Sheffield, S1 3JD, UK. Electronic address:
The nature of the atomic structure of many non-crystalline materials remains a long-standing open question. We use X-ray scattering to model electron images of amorphous materials, where the analogue 'atoms' consist of 1 μm diameter glass beads. The beads form a substantially random close-packed structure, but are partially ordered in places.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!