Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

Abstract

Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.

Phase-Based Alignment and Improved Projection Matching of Parallel Beam Tomography Data

“…Our data is provided via a recently published open access data project [22]. The projections are acquired by rotating around a single access, and the relative angles are given at ±75 • at every 2 • (although there are two missing angles that can be observed at 23 • and 25 • ).…”

Tutorial on the Visualization of Volumetric Data Using tomviz

“…Ultimately, the final visualization will depend on the questions, goals, and aesthetic of the researcher. Readers are encouraged to explore these techniques further using their own datasets, or using publicly available STEM tomography datasets [10]. …”

“…Surfaces are rendered in a single color. By default, this color will change as the intensity of [10] at different values of intensity and surface opacity. At full opacity, only the exterior of a surface contour is visible.…”

“…Varying the opacity at lower intensity allows the user to see through the exterior surface and observe the interior surfaces of the nebulous internal pore structure of the particle. Figure 2: A volumetric reconstruction of platinum nanoparticles on a carbon nanofiber [10], showing the position of an extracted orthogonal slice. In the extracted slice, platinum nanoparticles (white/orange) can be identified on both the interior and exterior surfaces of the nanofiber (magenta).…”

“…This animation shows a mixed volume and surface rendering of platinum nanoparticles decorating a carbon nanofiber of ~170 nm in diameter. The carbon fiber is visualized in black using a volume render, with the color-opacity map set such that only voxels Figure 4: Volume renderings of a Co 2 P nanoparticle [10] viewed from different perspectives using Grayscale, Plasma, and Viridis color-opacity maps. In these renderings, the dense internal core of the nanoparticle is displayed in lighter, more opaque colors, whilst the branches that protrude from the core are displayed as darker and more transparent colors.…”