Marm Dixit, an Alvin M. Weinberg Fellow, earned his PhD from Vanderbilt University. His dissertation focused on investigating processing–structure–function relationships in solid-state batteries. Marm’s thesis provided insight into failure mechanisms for several prevalent material alternatives of solid electrolyte as well as design rationales for achieving improved performance of solid-state batteries. These pivotal material technologies will enable electrification of the transportation sector and provide affordable, high energy density (HED), durable, and safe energy storage. Marm’s mentor is Ilias Belharouak, Electrification and Energy Infrastructure section head in the Electrification and Energy Infrastructure Division.
Working in the Emerging and Solid-State Batteries Group, Electrification and Energy Infrastructures Division, Marm will focus his fellowship research on evaluating and understanding the fundamental behavior of novel solid electrolyte materials against metallic anodes and high-voltage cathodes to generate insights that can be leveraged into high-performance devices. He will also investigate the influence of component fabrication routes, device integration steps, and operation protocols on device performance to provide energy storage solutions with techno-economic feasibility. His project is expected to enable scalable production of HED solid-state batteries that significantly impact the mobility industry and help in the electrification of the sector. In fall 2021, Marm was awarded a Toyota Young Investigator Fellowship for Projects in Green Energy Technology from the Electrochemical Society. The fellowship provides funding for young scientists and engineers to pursue battery and fuel cell research with an emphasis on unique, innovative, or unconventional technical approaches and the feasibility of the technology to positively impact the field of green energy. His ongoing research interests include energy storage and conversion, electrochemistry, synchrotron/neutron science, imaging, heterogeneous catalysis, and big data and machine learning.
Addis Fuhr, an Alvin M. Weinberg Fellow, earned his PhD from the University of California–Los Angeles. His dissertation focused on elucidating the electronic, optical, and magnetic properties of defects in quantum dots, and theory–experiment matching. Ternary copper-based quantum dots have unusual physical properties, making it difficult to determine how to optimize them for different applications. He helped unravel the mysterious origins of their unusual electronic, optical, and magnetic properties by combining theory with experiment to reveal mechanisms for defect formation and corresponding physics. His research helped improve the performance of CuxIn2-xSeyS2-y quantum dots for applications such as solar windows, solar cells, field-effect transistors, and light-emitting diodes. Addis’s mentor is Bobby Sumpter, ORNL Corporate Fellow and Theory and Computation section head in the Center for Nanophase Materials Sciences (CNMS).
Working in the Nanomaterials Theory Institute in CNMS, Addis is researching ways to integrate machine learning with ab initio computational chemistry and experimental materials characterization methods to enrich our understanding of the chemistry and physics of heterogeneity and defects in materials and to accelerate the discovery of materials with specific, desired functionality. His project is expected to enable accelerated discovery and understanding of the physics and chemistry of defects and heterogeneity in complex materials for applications such as multiferroics, quantum materials, solar energy, and battery, refractory, or nuclear materials. Addis’s ongoing research interests include combining theory with experiment to understand structure–property relationships for defects, heterogeneity, and coexisting phases in materials. He also is interested broadly in using theory/artificial intelligence to predict experimental signatures, and aiding in the design of materials with target functionalities.
Jake Nichols, an Alvin M. Weinberg Fellow, earned his PhD from Princeton University. His dissertation focused on modeling the erosion, transport, and redeposition of wall materials in magnetic fusion devices that utilize multiple materials for plasma-facing components and examining how these materials temporally evolve into mixed-material surfaces. His thesis clarified the mechanisms that limit the lifetime of thin film–conditioning techniques that are frequently applied to the walls of magnetic fusion devices to control impurities. This understanding will allow for more targeted conditioning of the wall surfaces, enabling present fusion devices to operate at higher performance for a longer period of time between maintenance phases. Jake’s mentor is Zeke Unterberg, Power Exhaust and Particle Control group leader.
Working in the Power Exhaust and Particle Control Group, Fusion Energy Division, Jake will focus his fellowship research on developing novel models for filamentary plasma transport in the edge of magnetic fusion devices that incorporate advanced divertor regimes and realistic 3D wall geometries, helping to constrain estimates of the heat and particle fluxes that will strike different parts of the vessel wall in a pilot plant–scale fusion device. His project is expected to advance optimization of the main wall of a fusion reactor by shaping the wall geometry such that the strongest fluxes are concentrated on components designed for the task. This approach will improve component reliability while reducing overall reactor cost. Jake’s ongoing research interests include plasma–material interactions, tokamak edge and divertor plasma physics, and integrated modeling of fusion systems.
Alice Perrin, an Alvin M. Weinberg Fellow, earned her PhD from Carnegie Mellon University. Her dissertation focused on the characterization of high-entropy alloys for magnetocaloric applications. Alice developed the first high-entropy alloy studied for magnetocaloric properties and demonstrated that the distribution of magnetic exchange interactions caused by the spread of dissimilar atoms on a single lattice favorably broadened the magnetocaloric response. Alice’s mentor is Ying Yang, a research scientist in the Materials Science and Technology Division.
Working in the Microstructural Evolution Modeling Group, Materials Science and Technology Division, Alice will focus her fellowship research on studying the effects of irradiation on grain boundary segregating nanocrystalline alloys; typically, solute segregation in nuclear materials reduces ductility and leads to embrittlement, but materials stabilized by high segregation energies that lead to equilibrium microstructures in which solutes decorate grain boundaries by design have not been studied for radiation tolerance. The small, thermodynamically stabilized nanocrystalline grain size of these alloys should increase their radiation tolerance due to the large area of grain boundaries that act as defect sinks. Her work will focus on understanding the segregated solutes’ behavior under irradiation and the resulting changes in microstructure and grain size, phase stability, and radiation hardening in this class of alloys. This research will potentially open up a new avenue of radiation-tolerant alloy design that takes advantage of new types of microstructures that utilize solute segregation as a feature instead of a bug. Alice’s ongoing research interests include nonequilibrium processing, thermodynamic and kinetic stabilization of metallic microstructures, functional alloy design for radiation resistance, and electrical and magnetic properties; additive manufacturing; and high-entropy alloys.
Bryan Piatkowski, a Liane B. Russell Fellow, earned his PhD from Duke University. His dissertation focused on the evolution and ecology of Sphagnum peat mosses, a group of plants that have extraordinary impact on global carbon cycling and engineer peatland ecosystems through traits such as cell wall biochemistry. Bryan’s thesis documented how functional traits evolved in Sphagnum and demonstrated the role of natural selection in shaping patterns of variation among species. Bryan’s mentor is Dave Weston, a staff scientist in the Biosciences Division.
Working with the Plant Systems Biology Group, Biosciences Division, Bryan will use evolutionary techniques to better understand how plants respond to challenging environmental conditions and identify the genetic components of stress tolerance that are shared across levels of biological hierarchy. Bryan’s project is expected to produce a comparative framework to integrate genetic discoveries from disparate model organisms and facilitate the translation of such findings into novel systems. He will also establish new capabilities to model the evolution of gene-to-trait associations and study how plants interact with their environment. Bryan’s ongoing research interests include understanding how organismal complexity emerges from genetic variation and linking microevolutionary processes, such as mutation, to macroevolutionary consequences like speciation.
Logan Sturm, an Alvin M. Weinberg Fellow, earned his PhD from Virginia Tech. His dissertation focused on cyber-physical security for additive manufacturing systems. Logan’s thesis provided a framework for identifying and mitigating sabotage attacks on additively manufactured parts using in situ monitoring, new techniques for securely transmitting part quality information to air-gapped side-channel monitoring systems, and an impedance-based method of nondestructively evaluating additively manufactured parts for defects. Logan’s mentor is Mason Rice, Resilient Complex Systems section head in the Cyber Resilience and Intelligence Division.
Working in the Embedded Systems Security Group, Cyber Resilience and Intelligence Division, Logan will focus his fellowship research on identifying cybersecurity vulnerabilities in additive manufacturing systems and developing techniques and platforms to mitigate the vulnerabilities. His work will include evaluating in‑process monitoring systems for metal laser powder bed fusion in an adversarial setting, developing new methods for improving the robustness of these systems to attacks, and investigating human factors and training to improve awareness and understanding of cybersecurity threats in manufacturing. Logan’s project is expected to provide improved security for manufacturing systems and increased awareness of the threats facing modern digital manufacturing. Logan’s ongoing research interests include in situ monitoring for additive manufacturing systems, vulnerability assessment in advanced manufacturing, data analytics for malicious defect detection, secure distributed manufacturing, unclonable security features for anticounterfeiting, and human–machine interactions in a cybersecurity context.
Trevor Aguirre, an Alvin M. Weinberg Fellow, earned his PhD from Colorado State University. His dissertation focused on investigating the architecture of biomechanically adapted unique porous bone architectures, including the trabecular architecture in the hind limbs of extant (e.g., elephant, rhinoceros) and extinct (mammoth and dinosaur) animals with large body mass, as well as the velar bone in Rocky Mountain Bighorn sheep horns. Trevor’s master’s degree focused on ceramics and ceramics processing. Understanding bones mechanics has informed his work engineering strong, lightweight structures, and his knowledge of ceramics is a natural fit with additive manufacturing. His mentor is Vlastimil Kunc, Advanced Composites Manufacturing group leader in the Manufacturing Science Division.
Working in the Advanced Composites Manufacturing Group, Manufacturing Science Division, Trevor will focus his fellowship research on additive manufacturing of high-performance ceramics composed of refractory and ultrahigh-temperature ceramic materials and processing effects on microstructure, mechanical, thermal, and thermomechanical performance for use in power generation. His work is expected to develop novel processing techniques compatible with additive manufacturing to produce ceramic heat exchanger materials that will increase energy conversion efficiency in power generation processes. Trevor’s ongoing research interests include understanding how the microstructures of additively manufactured ceramics can be tailored to withstand harsh environments necessary for efficient power generation.
Andrea Delgado, a Eugene P. Wigner Fellow, earned her PhD from Texas A&M University. Her dissertation focused on proving/disproving the existence of a particle not contained in the standard model of particle physics through the analysis of data collected by the Compact Muon Solenoid experiment at CERN, the European Organization for Nuclear Research, in Switzerland. The existence of such a particle would help alleviate discrepancies in results produced by the Large Hadron Collider beauty (LHCb) experiment, also at CERN. Andrea’s research at ORNL is interdisciplinary, focused on the intersection of quantum computing and particle physics. Her mentor is Marcel Demarteau, Physics Division director.
Working in the Nuclear Structure and Nuclear Astrophysics Group, Physics Division, Andrea will focus her fellowship research on quantum computing applications to high-energy physics. This work combines a scientific interest in extending our knowledge of the fundamental blocks of the universe and how they interact with each other and building better tools to analyze the data from large-scale particle physics experiments such as the LHC. Andrea’s research interests include developing data analysis tools for high-energy physics experiments, including machine learning and quantum computing. Andrea was a National Science Foundation Graduate Research Fellow and a National GEM Fellow at Fermi National Accelerator Laboratory before becoming a Distinguished Staff Fellow.
Stephen Taller, an Alvin M. Weinberg Fellow, earned his PhD from the University of Michigan. His dissertation focused on how accelerated damage rate experiments in the laboratory can capture the relevant processes that occur in structural materials in a nuclear reactor. Stephen used multiple ion beams simultaneously bombarding a target as a source of radiation damage at a rate 1,000× higher than test reactors to isolate the roles of temperature, damage rate, and helium co-generation rate in the nucleation of cavities that lead to the life-limiting degradation mode of irradiation-induced swelling. His work also involved developing a physical model to speculate where helium resides in the microstructure of ferritic-martensitic steel after irradiation. His mentor is Christian Petrie, Advanced Fuel Fabrication and Instrumentation group leader in the Nuclear Energy and Fuel Cycle Division.
Working in the Advanced Fuel Fabrication and Instrumentation Group, Nuclear Energy and Fuel Cycle Division, Stephen generates methods to shorten the development cycle of new materials for service with nuclear technologies. His work aims to bring the test and learn phases of materials evaluation in line with recent improvements in the design and manufacture phases. Stephen also focuses on the development and application of techniques for automating microscopy data acquisition and using machine learning to enhance the understanding of the relationships between the radiation-damaged microstructure observed at the nanoscale and their macroscale mechanical properties. The techniques developed will help reduce the time spent on postirradiation examination to increase the amount of knowledge gained per design cycle. Stephen’s ongoing research interests include understanding the life-limiting processes in materials for nuclear power reactor designs and how the microstructure of a material can be tailored to withstand the high temperatures and intense radiation fields expected in advanced reactors.
Andrew Ullman, a Eugene P. Wigner Fellow, earned his PhD from Harvard University. His dissertation focused on polynuclear cobalt complexes as models of a cobalt-based water oxidation catalyst. Using molecules to study structural and electronic analogs of an amorphous cobalt-oxide catalyst, he provided atomic-level insight into the mechanism of water oxidation at neutral pH, specifically pertaining to the contribution of the anionic electrolyte species beyond their role as proton acceptors. This work provided the understanding needed to further optimize the activity of metal-oxide–based water oxidation catalysts in neutral pHs. Andrew’s mentor is Jagjit Nanda, Energy Storage group leader in the Chemical Sciences Division.
Working in the Energy Storage Group, Chemical Sciences Division, Andrew’s fellowship research will introduce a new type of solid-state electrolyte to the battery research field that has high single-ion conductivity, forms a stable interface with lithium metal anodes, enables uniform stripping and plating of lithium, and ultimately, is incorporated into a high-energy, inherently safe, solid-state battery. Such batteries have the potential to revolutionize the future of electro-mobility. Andrew’s ongoing research interests include applying synthetic chemistry to problems related to the movement of electrons (quantum particles) and ions (classical particles), which span the fields of energy storage, batteries, catalysis, and quantum information systems. He held a postdoc position at Sandia National Laboratories and developed battery separator coating materials for lithium ion and lithium metal batteries at battery start-up Sepion Technologies.
Friederike Bock, a Eugene P. Wigner Fellow, earned her PhD through a joint program of Lawrence Berkeley National Laboratory and the University of Heidelberg. Her dissertation focused on heavy ion physics and establishing the point at which the quark-gluon plasma can be seen during heavy nucleus collisions. Friederike’s work established new techniques aimed at reducing uncertainty in collision systems with variable thermal signal strengths. Her project represented the first effort to look at direct photons in proton–proton and proton–lead collisions at the Large Hadron Collider at CERN, the European Organization for Nuclear Research, in Switzerland. Friederike’s mentor is Tom Cormier, Relativistic Nuclear Physics group leader in the Physics Division.
Friederike’s fellowship research in the Heavy Ion Reactions Group will focus on producing very precise measurements of the photon signal in heavy ion and intermediate collision systems and on building a new detector that she hopes will unveil a new state of matter, gluonic matter, in currently uncharted phase space areas. Her ongoing research interests also include understanding photons from a more phenomenological perspective, thus bridging the gap to theoretical calculations.
Victor Fung, a Eugene P. Wigner Fellow, earned his PhD from the University of California–Riverside. His dissertation focused on using first-principles computational chemistry to study alkane conversion on heterogeneous catalysis. His work provided mechanistic insights and chemical descriptors that can be used for discovering and designing better catalysts to break C–H bonds. Victor’s mentor is Bobby Sumpter, Theory and Computation section head in CNMS.
Victor is based at CNMS’s Nanomaterials Theory Institute. His fellowship research involves obtaining fundamental physicochemical descriptors of chemical properties, conducting high-throughput materials screening and developing machine learning methods for materials discovery and design. Specific topics of his research include the capture and conversion of methane, heterogeneous C–H functionalization, and the structure/property prediction of nanomaterials. His research interests lie at the intersection of probing physical and chemical phenomena such as chemical bonding and developing computational tools that guide scientists to the most promising materials for physical study.
Gang Seob “GS” Jung, a Eugene P. Wigner Fellow, earned his PhD from the Massachusetts Institute of Technology. His dissertation focused on developing multiscale models to understand fracture and synthesis processes of 2D materials such as graphene, tungsten disulfide, and molybdenum disulfide. He examined computationally how these materials behave when such 2D crystals structurally fail or form grain boundaries at the atomic level, to understand fundamental mechanisms and continuum-scale properties. GS’ models have effectively explained and predicted 2D material behaviors observed in experiments. His mentor is Stephan Irle, Computational Chemistry and Nanomaterial group leader in the Computational Sciences and Engineering Division (CSED).
In the Computational Chemistry and Nanomaterial Group, GS develops integrated multiscale models that enable predictive design and simulation of materials of interest at ORNL. He explores atomic-scale, mesoscale, and continuum-scale characteristics of materials to understand how multiscale properties and behaviors define performance. GS’ research interests include building a virtual lab where materials can be synthesized and characterized by combining and bridging advanced computational methods at different scales using ORNL’s world-leading high-performance computing resources.
Joe Paddison, a Eugene P. Wigner Fellow, earned his PhD from the University of Oxford. His dissertation involved using computational modeling techniques to predict 3D scattering data from powder data when crystals of materials under study cannot be derived. Joe’s work showed that unexpected amounts and types of information can be obtained from neutron scattering measurements. His mentor is Andy Christianson, a neutron scattering scientist in the Materials Science and Technology Division.
Joe’s work in the Scattering and Thermophysics Group will focus on using neutron scattering techniques to develop a deeper understanding of the behavior of magnetic materials such as quantum-spin liquids. He aims to explore materials for which the effects of quantum mechanics and crystalline geometry coincide to create new states of matter featuring entangled magnetic states. Joe was awarded the 2021 BTM Willis Prize by the UK Neutron Scattering Group in recognition of his contributions to the study of frustrated (i.e., disordered) magnetic materials using diffuse neutron scattering. Joe’s research interests lie at the intersection of neutron scattering, materials’ structure and characteristics, and models of materials’ behavior.