Emergent Materials under Extremes and Decisive In Situ Characterizations: On-Demand Oral Presentations
Sponsored by: ACerS Basic Science Division
Program Organizers: Hongwu Xu, Los Alamos National Laboratory; Xiaofeng Guo, Washington State University; Xujie Lu, Center for High Pressure Science & Technology Advanced Research; Hua Zhou, Argonne National Laboratory; Judith Driscoll, University of Cambridge
Friday 8:00 AM
October 22, 2021
Room: On-Demand Room 7
Location: MS&T On Demand
Session Chair: Xiaofeng Guo, WSU; Hua Zhou, ANL; Hongwu Xu, LANL
Invited
Nanomechanic Characterizations with Diamond-Anvil Cell Techniques: Bin Chen1; Xiaoling Zhou2; Jianing Xu2; Hongliang Dong1; Yanju Wang1; Zongqiang Feng3; Xiaoxu Huang3; 1Center for High Pressure Science and Technology Advanced Research; 2Harbin Institute of Technology; 3Chongqing University
In recent years, we extended the explorations for the plastic deformation of nanomaterials by employing radial diamond-anvil cell XRD and TEM. We have successfully probed the lower grain size limit of dislocation activities. Our high-pressure studies reveal that dislocations are operative in nanoceramics. We have observed the reversal in the grain size dependence of grain rotation in nickel. It is detected that the strengthening of nickel nanocrystals can be extended down to 3 nm. Excitingly, we found that nanometals in a certain range of grain size exhibit both superplasticity and high strength. Compared with the traditional techniques, high pressure techniques are more advantageous in applying mechanical load to nanosized samples and characterizing the structural and mechanical properties in situ or ex situ, which could help unveil the mysteries of mechanics at the nanoscale and bridge the knowledge on the material mechanics at the multiscale.
Invited
Nanoparticles Under High Pressure: Assembly and Formation of Active Nanostructures: Hongyou Fan1; 1Sandia National Labs
Precise control of structural parameters through nanoscale engineering to improve optical and electronic properties of nanoparticles continuously remains an outstanding challenge. Previous work on nanoparticle assembly has been conducted largely at ambient pressure. Here I will present a new Pressure-Induced Assembly and Fabrication method in which we applied high pressure or stress to nanoparticle arrays to induce structural phase transition and to consolidate new nanomaterials with precisely controlled structures and tunable properties. By manipulating nanoparticle coupling through external pressure, a reversible change in their assemblies and properties has been achieved and demonstrated. Additionally, over a certain threshold, the applied pressure will force these nanoparticles into coalescence, thereby allowing the formation and consolidation of one- to three-dimensional nanostructures. Through pressure induced nanoparticle assembly, materials engineering and synthesis become remarkably flexible without relying on traditional crystallization process. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
Invited
Novel Properties in Cuprates Prepared by High Pressure Oxygen Synthesis: Steven Conradson1; 1Jozef Stefan Institute
Following the initial discovery of high temperature superconductivity in cuprates it was quickly established that doping by oxidation with O2 gave a nearly universal phase diagram characterized by a superconducting "dome" in which the material shifted from an AFM insulator to a superconductor at a charge on the Cu ions in the conducting CuO2 planes of ~2.06, exhibited maximum Tc at ~2.15, and ended with conversion to a normal Fermi liquid at ~2.26. However, oxidation with chlorate or peroxide at high temperature and pressure gives nominally the same compounds but with superconductivity extending through the maximum attainable O stoichiometries. These HPO materials exhibit a number of properties that question many of the assumptions of HTSC.
Invited
Structure and Composition of Novel Nitride Materials Synthesized at Extreme Conditions of High Pressure and High Temperature Determined by Single-crystal X-ray Diffraction and Raman Spectroscopy: Alexander Goncharov1; 1Earth and Planets Laboratory, Carnegie Institution for Science
Here I address synthesis of novel ultrahard, energetic, and functional materials created by design at extreme pressures and temperatures. Pressure is the critical parameter in this synthesis which unlocks structural diversity and unique physical properties thus enabling implications as new energy carriers, piezo/ferroelectic, 2D electronic, and superhard materials. The nitride properties also critically depend on the constituent elements and doping composition, which is the key element of this study. The examples will be given of various nitrides synthesized at extreme conditions, many of which can be recovered to ambient conditions. I acknowledge contributions of Maxim Bykov, Elena Bykova, Stella Chariton, Vitali Prakapenka, Jesse Smith.
New Approach Toward Enhanced Understanding of the Phase Transformation in Anodically Formed Titanium Oxide Nanotubes during Annealing: Hammad Malik1; Brian Devener1; Jerry Howard1; Swomitra Mohanty1; Krista Carlson1; 1University of Utah
Anodically formed titanium oxide nanotubes are subjected to annealing to induce crystallinity but sintering and crystal growth initiated at the titanium substrate surface during annealing causes morphological changes. We have developed a focused ion beam sample preparation procedure for an in situ transmission electron microscopy and scanning transmission electron microscopy annealing study of the interface between anodically formed titanium oxide nanotubes and titanium metal substrate using atmospheric e-chips (Protochips Inc.). In accordance with our previous findings, we observed nucleation of denser phases within the metal substrate and the growth of these crystallites through the metal-oxide interface and along the length of nanotubes. The in situ annealing investigation of the interface is critical for an enhanced understanding of governing mechanism behind phase transition kinetics and morphological changes during annealing. The in situ annealing study was done in the air and 2% hydrogen balance nitrogen environments.
Far-From-Equilibrium Processing of Materials under Extreme Conditions: Eric O'Quinn1; Alexandre Solomon1; Casey Corbridge1; Antonio Fuentes2; Maik Lang1; 1University of Tennessee; 2Cinvestav Unidad Saltillo
The fabrication of next generation energy materials requires comprehensive knowledge of material modifications under far-from-equilibrium. High energy ball milling and swift heavy ion irradiation are two unique processing routes that provide access to unconventional structural features which cannot be obtained by traditional synthesis techniques. Using bixbyite-structured lanthanide sesquioxides (Ln2O3) as a model system, we demonstrate the formation of a variety of defect structures and non-equilibrium phases that are inaccessible by other approaches. Different high-pressure and high-temperature phases form during the highly transient processing and transformation pathways can be adjusted by milling and irradiation parameters. The type of induced structural modifications strongly depends on the physics of interaction and detailed characterization of the resulting material modifications over a wide range of experimental conditions present a first step to understand and control matter far away from equilibrium.
Photoindentation: A New Route to Understanding Dislocation Behavior in Light: Atsutomo Nakamura1; Xufei Fang2; Ayaka Matsubara1; Eita Tochigi3; Yu Oshima1; Tatsushi Saito1; Tatsuya Yokoi1; Yuichi Ikuhara3; Katsuyuki Matsunaga1; 1Nagoya University; 2Technische Universität Darmstadt; 3The University of Tokyo
It was recently found that extremely large plasticity is exhibited in bulk compression of single-crystal ZnS in complete darkness. Such effects are believed to be caused by the interactions between dislocations and photo-excited electrons and/or holes. However, methods for evaluating dislocation behavior in such semiconductors with small dimensions under a particular light condition had not been well established. Here, we propose the “photo-indentation” technique to solve this issue by combining nanoscale indentation tests with fully controlled lighting system. The quantitative data analyses based on this photo-indentation approach successfully demonstrate that the first pop-in stress indicating dislocation nucleation near the surface of ZnS, clearly increases by light irradiation. Additionally, the room-temperature indentation creep tests show a drastic reduction of the dislocation mobility under light. Our approach demonstrates great potential in understanding the light effects on dislocation nucleation and mobility at the nanoscale, as most advanced technology-related semiconductors are limited in dimensions.
Investigation of Kirkendall Pore Formation and Evolution Using 4D Spatio-Temporal X-ray Tomography and Deep Learning: Arun Bhattacharjee1; Pradyumna Elavarthi1; Anca Ralescu1; Ashley Paz y Puente1; 1University of Cincinnati
In-situ synchrotron x-ray tomography was performed during pack titanization of 75 and 100 µm diameter Ni wires at 925 °C. Due to the imbalance of Ni and Ti intrinsic diffusivities, during Ti deposition there is a net flux of vacancies toward the radial center of the sample that eventually coalesce leading to the formation of Kirkandall pores. In many cases, a multi-pore structure develops within a particular cross-section and some of these pores appear to sinter to the surface while others continue to grow further. To better understand the mechanisms governing this pore development and evolution, a fully convolutional neural network inspired from the U-net architecture was trained using masks created from previous in-situ homogenization tomography data to track individual pores during Ti deposition. The network was also used to predict the pore and phase evolution on intermediate sizes of the samples for which experimental data was not available.