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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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DOE OSTI2022

Single-Step Fabrication of Au-Fe-BaTiO3 Nanocomposite Thin Films Embedded with Non-Equilibrium Au-Fe Alloyed Nanostructures

Nanocomposite thin film materials present great opportunities in coupling materials and functionalities in unique nanostructures including nanoparticles-in-matrix, vertically aligned nanocomposites (VANs), and nanolayers. Interestingly the nanocomposites processed through a non-equilibrium processing method, e.g., pulsed laser deposition (PLD), often possess unique metastable phases and microstructures that could not achieve using equilibrium techniques, and thus lead to novel physical properties. In this work, a unique three-phase system composed of BaTiO3 (BTO), with two immiscible metals, Au and Fe, is demonstrated. By adjusting the deposition laser frequency from 2 Hz to 10 Hz, the phase and morphology of Au and Fe nanoparticles in BTO matrix vary from separated Au and Fe nanoparticles to well-mixed Au-Fe alloy pillars. This is attributed to the non-equilibrium process of PLD and the limited diffusion under high laser frequency (e.g., 10 Hz). The magnetic and optical properties are effectively tuned based on the morphology variation. This work demonstrates the stabilization of non-equilibrium alloy structures in the VAN form and allows for the exploration of new non-equilibrium materials systems and their properties that could not be easily achieved through traditional equilibrium methods.

36 MATERIALS SCIENCE↗

DOE OSTI2023

DOE-VFP; Surface Engineered Multifunctional Zeolite Composite for Photodegradation of Per- and Polyfluoroalkyl substances (PFAS) in Aqueous Medium

Per- and Polyfluoroalkyl substances (PFAS) are widely used compounds proven to bioaccumulate and result in detrimental health effects. On October 18, 2021 the United States Environmental Pollution Agency (EPA) released a strategic roadmap to address PFAS that includes the investment in effective research that accelerates cleanup. Existing water treatment technologies for PFAS removal are based on adsorptive removal, are commonly single-use and result in pollutant-laden waste, leading to costly disposal processes. Here we proposed the development of a zeolite-TiO 2 composite for removal and degradation of PFAS. The composite is advantageous as it can be easily integrated into water treatment facilities, is multifunctional, and minimizes waste through regeneration. We studied the adsorptive capacity of zeolites 13X, 3A, 4A and 5A for an anionic PFAS surrogate, methyl orange (MO). Zeolite 3A showed the highest adsorptive capacity, followed by 4A, 5A, and 13X when incubated with 15 ppm MO for 3 hours. Depositing Au-nanospheres on the zeolites surface reduced MO adsorption for all zeolites. We also investigated the photodegradation capacity of TiO 2 , Fe 2 O 3 , Au-TiO 2 , and Au-Fe 2 O 3 , ranking their performance as TiO2 > Fe2O3 > Au-TiO 2 > Au-Fe 2 O 3 under 254 nm light in a 10 ppm MO solution. Our results highlight the favorable adsorption of small pore size zeolites for PFAS surrogates and the potential of TiO2 as a photocatalyst for PFAS degradation. We can further study and integrate the composite's components at our home institution. Other notable achievements of our VFP team includes the submission of two funding proposals, two poster presentations and one invited talk thus showcasing our progress.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2024

Imaging 3D chemistry at 1 nm resolution with fused multi-modal electron tomography

Measuring the three-dimensional (3D) distribution of chemistry in nanoscale matter is a longstanding challenge for metrological science. The inelastic scattering events required for 3D chemical imaging are too rare, requiring high beam exposure that destroys the specimen before an experiment is completed. Even larger doses are required to achieve high resolution. Thus, chemical mapping in 3D has been unachievable except at lower resolution with the most radiation-hard materials. Here, high-resolution 3D chemical imaging is achieved near or below one-nanometer resolution in an Au-Fe 3 O 4 metamaterial within an organic ligand matrix, Co 3 O 4 -Mn 3 O 4 core-shell nanocrystals, and ZnS-Cu 0.64 S 0.36 nanomaterial using fused multi-modal electron tomography. Multi-modal data fusion enables high-resolution chemical tomography often with 99% less dose by linking information encoded within both elastic (HAADF) and inelastic (EDX/EELS) signals. We thus demonstrate that sub-nanometer 3D resolution of chemistry is measurable for a broad class of geometrically and compositionally complex materials.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on FeAu3 by Materials Project

FeAu3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Fe3+ is bonded in a distorted body-centered cubic geometry to fourteen Au1- atoms. There are eight shorter (2.81 Å) and six longer (3.24 Å) Fe–Au bond lengths. There are two inequivalent Au1- sites. In the first Au1- site, Au1- is bonded to four equivalent Fe3+ and four equivalent Au1- atoms to form a mixture of distorted edge, face, and corner-sharing AuFe4Au4 tetrahedra. All Au–Au bond lengths are 2.81 Å. In the second Au1- site, Au1- is bonded in a 8-coordinate geometry to six equivalent Fe3+ and eight equivalent Au1- atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on FeAu by Materials Project

AuFe crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Fe is bonded to six equivalent Au atoms to form a mixture of distorted corner and edge-sharing FeAu6 cuboctahedra. All Fe–Au bond lengths are 2.77 Å. Au is bonded to six equivalent Fe atoms to form a mixture of distorted corner and edge-sharing AuFe6 cuboctahedra.

36 MATERIALS SCIENCE↗