Emergent Materials under Extremes and Decisive In Situ Characterizations: In Situ Characterization
Sponsored by: ACerS Basic Science Division
Program Organizers: Xiaofeng Guo, Washington State University; Hongwu Xu, Los Alamos National Laboratory; Xujie Lu, Center for High Pressure Science & Technology Advanced Research; Hua Zhou, Argonne National Laboratory; Judith Driscoll, University of Cambridge
Wednesday 8:00 AM
October 12, 2022
Room: 325
Location: David L. Lawrence Convention Center
Session Chair: Hua Zhou, Argonne National Laboratory
8:00 AM Introductory Comments
8:10 AM Invited
Structural Transformations Induced under Coupled Extreme Conditions: Maik Lang1; 1University of Tennessee
Materials research related to extreme conditions has become an important field due to its relevance for energy-related applications. Most often, one extreme environment is studied in isolation, but recent research has demonstrated that materials behavior and induced structural modifications dramatically change if extremes are coupled simultaneously and not applied separately. Diamond anvil cell technology has been successfully utilized at large ion accelerators allowing materials to be exposed to extremely high pressures and temperatures and swift heavy ion irradiations at once. This presentation describes state-of-the-art science in this field by presenting several examples of structural modifications induced by coupled extreme conditions, including most recently developed in situ characterization capabilities. This innovative experimental approach allows us to form and stabilize novel phases in a wide range of oxides (e.g., Gd2Zr2O7), study fission-track formation under geologically relevant crustal conditions, and investigate phase transitions of damaged minerals resulting from meteorite impact (e.g., ZrSiO4).
8:40 AM Invited
Characterization of Disordered Oxides with Neutron Total Scattering: Eric O'Quinn1; 1University of Tennessee
Oxide materials proposed for use in a wide variety of current and next-generation energy technologies require a comprehensive understanding of how their structure is modified across all length scales by exposure to extreme conditions (e.g., ion exposure, high temperatures, and variable chemical composition). We demonstrated previously that neutron total scattering experiments with pair distribution function (PDF) analysis coupled with Reverse Monte Carlo (RMC) modeling is an ideal tool for characterizing defective and highly disordered materials from the atomic scale to the long-range structure. The new insight that characterization with spallation neutrons provide, is shown with three representative examples: (1) amorphous complex oxides relevant for nuclear waste research (e.g., waste glasses and A2B2O7 pyrochlore oxides), (2) disordered, crystalline complex oxides related to fuel cell and battery research (e.g., A3BO7 fluorite and AB2O4 spinel oxides), and (3) defective, crystalline simple oxides utilized as nuclear fuels (e.g., UO2+x hyperstoichiometric oxides).
9:10 AM Invited
In-Situ X-ray Absorption Spectroscopy of Actinide Speciation in Aqueous Fluids at Extreme Conditions: Robert Mayanovic1; Jason Baker2; Diwash Dhakal1; Nadib Akram1; Xiaofeng Guo3; Hakim Boukhalfa2; Cheng-Jun Sun4; Hongwu Xu2; 1Missouri State University; 2Los Alamos National Laboratory; 3Washington State University; 4Argonne National Laboratory
There are scarce data on the molecular structure and stability of aqueous actinide species at high P-T conditions. Such data are critical for development of accident-tolerant fuels and to address issues pertaining to high-level waste disposal. In-situ X-ray absorption spectroscopy (XAS) and related spectroscopic studies of actinide species in aqueous fluids, containing chloride, carbonate and other ligands, are needed to determine the stability and speciation of actinides under high P-T-γ (γ: radiation) conditions. Our in-situ U LIII edge XAS investigations of uranyl chloride and uranyl carbonate aqueous solutions, at temperatures from 25 to 500 °C, will be discussed. The XAS measurements are made using the hydrothermal diamond anvil cell housed in a 3-layer containment. Analysis of the XAS data confirms that the aqueous uranyl chloride complexes trend toward charge neutral species with increasing temperatures. Conversely, our analysis shows that the uranyl carbonate complexes are stable only to ~ 100 °C.
9:40 AM Invited
Opportunities in High-pressure Science Enabled by Next Generation Synchrotron Sources: Jesse Smith1; 1HPCAT, Argonne National Laboratory
The characteristics of synchrotron radiation sources – a high flux of high energy photons in a highly parallel beam – make them an indispensable tool for the study of materials at extreme conditions. Each generational improvement in synchrotron sources has opened up new and extended research avenues in high-pressure science. In this presentation I will highlight some key improvements to the Advanced Photon Source (APS) as it is upgraded to a latest-generation synchrotron source – characterized by the use of a multi-bend achromat lattice – and how these improvements will significantly improve the spatial and temporal resolution accessible for high-pressure research at HPCAT (High Pressure Collaborative Access Team, Sector 16, APS). I will review recent results from HPCAT users which approach the limits of the current spatial and temporal resolution of the 3rd generation source, and explore future opportunities expected to follow the concurrent APS and HPCAT upgrades.
10:10 AM Break
10:30 AM
Determination of P-V Equation of State of a Natural Clinoptilolite Using High Pressure Synchrotron X-ray Diffraction: Andrew Strzelecki1; Stella Chariton2; Cody Cockerham1; Vitali Prakapenka2; Bethany Chidester1; Di Wu3; Chris Bradley1; Garrett Euler1; Xiaofeng Guo3; Hakim Boukhalfa1; Hongwu Xu1; 1Los Alamos National Laboratory; 2University of Chicago; 3Washington State University
The compression behavior of a natural HEU type zeolite, clinoptilolite, was investigated in the pressure range of 0–15 GPa using in-situ synchrotron powder XRD with a diamond-anvil cell. Clinoptilolite underwent pressure induced amorphization when the pressure exceeded 9.04 GPa and was deemed fully amorphous at 14.65 GPa. Rietveld analyses of the XRD data allowed determination of its unit-cell parameters as a function of pressure. The resulting fit to the second order Birch-Murnaghan equation of state for the clinoptilolite yielded a V0 of 2094 ± 8 ų and a K0 of 34.4 ± 1.4 GPa. The zero-pressure compressibilites of its a, b, and c axes are 10.6 (± 0.8) × 10–3 GPa–1, 5.3 (± 0.7) × 10–3 GPa–1, and 17.1 (± 1.8) × 10–3 GPa–1, respectively. The derived bulk moduli and linear compressibilites indicate that the compression behavior of clinoptilolite is highly anisotropic.
10:50 AM
Novel Automated Approaches for Studying Extended In Situ Mechanical and High Temperature Transformations of New Materials and Alloys in Scanning Electron and X-ray Microscopy: Andy Holwell1; Fang Zhou1; 1Carl Zeiss Microscopy LLC
Energy Dispersive X-ray Spectroscopy and Electron Backscatter Diffraction have become ubiquitous in characterizing new materials and alloys in the SEM. Extending these techniques with time-resolved in situ mechanical and thermal testing, allows researchers to observe and characterize materials' transformations at the nanoscale, in real time, with forces modelling real-world service conditions. Also, performing synchrotron-style in situ 3D imaging and crystallography in the X-ray microscope through time-resolved absorption and diffraction contrast tomography allows quantitative 4D imaging of transformations. This work describes the evolution of strain, dislocations and crystal structure in materials including polymers, foams, explosives, GaN, superalloy and steel. Combination of an in situ rig, dedicated high-temperature SE, BSE, EDS and EBSD detectors and electron channelling contrast provide comprehensive analytics of microstructural behavior of stressed samples.Digital image correlation and automated feature tracking overcome barriers to consistent imaging and tracking of dynamic features, enabling long unattended transition studies.