Eyring Materials Center

Ondrej L. Krivanek, Bruker AXS and ASU

Combining three things — fertile soil, winter rains, and the right kinds of established plants and ambitious new seeds — creates beautiful blooms in the Arizona desert every spring. The blooming of electron microscopy at ASU followed a similar path, with the Eyring Materials Center furnishing the fertile soil, NSF and other agencies sending us infrequent but essential funding rains, and established scientists as well as talented new seeds sprouting remarkable blooms. The blooms gave rise to new seeds and rich harvests in many other places where they were planted. My brief talk will review some of the early blooms ASU cultivated in the 1970s and 80s and place them in the wider context of other developments that transformed electron microscopy.  

Bio

Ondrej Krivanek is a co-founder and ex-president of Nion Co., a maker of advanced electron microscopes, which was recently acquired by Bruker. He is well known for developing several new instruments that have endowed electron microscopes with revolutionary new capabilities, such as electron energy loss spectrometers and imaging filters, aberration correctors, advanced monochromators and whole electron microscopes. Examples of research made possible by these instruments include imaging and analyzing the bonding properties of single atom impurities in materials, and opening up the field of vibrational spectroscopy in the electron microscope, with very high spatial resolution. His work has been honored by several prizes and honorary fellowships and doctorates, including an election to the UK Royal Society, and the 2020 Kavli Prize for Nanoscience.

Renu Sharma, National Institute of Standards and Technology and ASU

LeRoy Eyring joined ASU as chair of the chemistry department after having worked at various academic institutions in Europe and Australia. The international experience probably helped him envision a future for collaborative research across different disciplines and institutes and led him to seek funding to establish the Center for Solid State Science, which evolved into the current Eyring Materials Center. His research was centered around the structures of rare earth oxides, such as cerium, praseodymium and terbium oxide. Ordered oxygen vacancies in these oxides results in materials with complicated structures with large unit cells that were difficult to solve with traditional X-ray diffraction technique. This led him to include TEM as one of the characterization techniques in the Center for Solid State Science. He was also instrumental in bringing Professor Cowley, under whose supervision the National Center for Transmission Electron Microscopy was established with the help of a grant from NSF. His research group utilized TEM-based techniques not only to decipher the oxides with long range ordered vacancies but also to understand their formation mechanism using “in situ” electron beam heating. He also realized that electron beam is not ideal for controlled experiments and travelled to NCEM to utilize their environmental cell TEM (Kratos). I joined his group in 1985 to perform such in situ observations and develop environmental TEM for controlled heating experiments in gaseous environments. I will present some examples spanning from the early days of electron beam heating to the controlled experiments and their contribution to our understanding of oxide chemistry.

Bio

Renu Sharma is one of the pioneers in the development of environmental scanning transmission electron microscopy (E(S)TEM). She received a BS and BEd in physics and chemistry from Panjab University, India, and MS and PhD degrees in solid state chemistry from the University of Stockholm, Sweden, where she had a Swedish Institute Fellowship. Sharma joined the National Institute of Standards and Technology as a project Leader in 2009, coming from ASU, where she modified two TEM columns to function as an ETEM. At ASU, she was a research scientist in the Department of Chemistry and Biochemistry and the Center for Solid State Science, and an affiliated faculty member in the School of Materials and the Department of Chemical Engineering. She has written one book on in-situ TEM and is lecturer at the ASU Winter School. Sharma is a fellow of the Microscopy Society of America, has received a Bronze Medal of Service from the U.S. Department of Commerce for developing new measurement techniques and a Deutscher Akademischer Austauschdienst Faculty Research Fellowship, and is past president of the Arizona Imaging and Microanalysis Society. At NIST, Sharma established advanced E(S)TEM measurement capabilities that combine Raman and cathodoluminescence spectroscopies with electron diffraction, electron spectroscopy and high-resolution imaging (ETEM Lab). She is now an emeritus NIST fellow and emeritus scientist at ASU.

Richard L. Hervig, School of Earth and Space Exploration, ASU 

Peter Williams and colleagues were awarded funds to purchase a secondary ion mass spectrometer in the 1980s. Because of Pete’s interest in collaborative research, he wanted to open his lab to many scientists. Because of my familiarity in this field, I was hired in the center in the late 1980s to provide access to this complex instrument. I will describe the results of that decision, in terms of the collaborative interdisciplinary research, teaching/training of students, multiple services to the community, and recognition of ASU as a leader in this technique.

Bio

Richard (Rick) Hervig received his BS in 1975 from the University of Iowa (geology) and his PhD from the University of Chicago (geophysical sciences) in 1979. He worked in nuclear waste disposal at what is now Pacific Northwest National Lab before taking a position with Alex Navrotsky at ASU in 1981, where he studied the thermodynamic properties of glasses and minerals. He was hired in the predecessor to the Eyring Materials Center (Center for Solid State Science) as an assistant research scientist in 1987, and left this center in 2004 to take a position as professor in the Department of Geological Sciences (now the School of Earth and Space Exploration).

Hervig has developed new analytical techniques in secondary ion mass spectrometry and has made significant improvements in instrument performance through implementation of novel designs. He has contributed six chapters to Reviews in Mineralogy and Geochemistry volumes concerning the applications of SIMS to geochemical and cosmochemical problems. Hervig’s collaborative research with electrical engineers has presented new ways of applying SIMS to problems in earth science. Besides training researchers in the use of SIMS, he also teaches classes in petrology, geochemistry, nuclear forensics, science communication and analytical instrumentation to chemistry, engineering and geology students.

Jian-Min Zuo, Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois Urbana-Champaign

The recent developments in electron optics and fast detectors have revolutionized the way materials are characterized at the atomic and nm scale. Through the collection of massive diffraction datasets and by data mining the hyperspectral datasets, a material’s atomic, electronic and magnetic structure can be characterized in a quantitative way, and yet at unprecedented resolution and details. This form of data-driven electron microscopy is fundamentally different from traditional imaging approaches that were based on lenses and apertures. This talk will showcase the advances in data-driven electron microscopy and highlight Eyring Materials Center contributions in pioneering scanning transmission electron microscopy, electron nanodiffraction and quantitative convergent-beam electron diffraction — the components in four-dimensional STEM. It will show the essential role of a centralized facility, academic curiosity and collaborations in advancing modern materials science.

Bio

Jian-Min Zuo is the Ivan Racheff Professor of Materials Science and Engineering at the University of Illinois, Urbana-Champaign. He received his PhD in physics from ASU in 1989. At the University of Illinois, he and his research group pioneered the atomistic structure study of nanostructured materials, ultrafast electron diffraction, interfaces and chemical bonding, through the development of coherent electron nanodiffraction, aberration-corrected electron imaging and scanning electron nanodiffraction techniques. Zuo is a fellow of American Physical Society and Microscopy Society of America, a recipient of Ernst Ruska Prize of the German Society for Electron Microscopy and Gjonnes Award from International Union of Crystallography. He is the author, with John CH Spence of ASU, of the 2017 book, “Advanced Transmission Electron Microscopy: Imaging and Diffraction in Nanoscience,” published by Springer.

Moon J. Kim, Department of Materials Science and Engineering, the University of Texas at Dallas

With the advancement of technology and computational methods in the era of the materials genome, the exploration of new and emerging materials for potential applications has accelerated. The use of non-conventional processes and non-equilibrium conditions in material fabrication and processing presents unique opportunities to discover novel material phases beyond the predictions of traditional phase diagrams and theoretical models. In particular, atomic-resolution electron microscopy, combined with in-situ capabilities, serves as a powerful tool for uncovering these new phases.

In this presentation, I will discuss two recently discovered material phases:

• Mo₆Te₆ nanowire
• Two-dimensional tellurium (Tellurene)

Additionally, I will introduce NanoArt, an emerging discipline that highlights the artistic beauty of natural and engineered nanometer-scale materials. I will showcase a selection of my NanoArt collections, including AI-stylized pieces and the “NanoArt-In-Motion” series, which blends the visual elegance of NanoArt with the fluidity of choreographed dance.

Bio

Moon Kim’s research and technical expertise focus on nanofabrication and the manipulation and characterization of materials and devices for electronic and photonic applications. His expertise includes high-resolution electron microscopy, wafer bonding technology and 3D functional nanostructures and nanodevices. As an expert in nanotechnology in the 1990s, Kim became one of the first researchers in the world to build an ultra-high vacuum wafer bonding instrument. That machine, now housed in the Natural Science and Engineering Research Laboratory, was a cornerstone to enabling groundbreaking research in the region, international collaborations and the attainment of more advanced equipment and world-class professors.

Jingyue (Jimmy) Liu, Department of Physics, ASU 

Catalysis is used to produce a broad range of products, including fuels, plastics, pharmaceuticals, chemicals/agrichemicals and other functional materials. To achieve a future of a renewable, circular and sustainable society, it is imperative to understand the intrinsic nature of active sites in heterogeneous catalysis and construct the most desirable active sites for chemical transformations of molecules. The essential role of solid catalysts is to efficiently facilitate the targeted molecular reactions, reduce toxic/waste side products and lower production costs. Figuring out precisely where the active sites on a practical solid catalyst are has been a formidable challenge since the idea that only specific sites on a catalyst surface are responsible for reactions was introduced by Taylor in 1925. The aberration-corrected scanning transmission electron microscope (ac-STEM) is one of the most powerful tools for identifying the nature of active centers of solid catalysts and for optimizing catalyst synthesis processes. The discovery and development of single-atom catalysis was primarily driven by the capabilities of ac-STEMs, allowing direct visualization and analysis of isolated metal atoms on a support material and their structural relationship to the neighboring atoms of the support surface. With the growing understanding of the unique catalytic properties of isolated metal atoms (active sites), particularly their strong interactions with the support atoms (ligands), and the rapid advances of scalable synthesis methods to produce single-atom catalysts (SACs), we have been witnessing the rapid progress of understanding catalytically active centers of solids and the development of highly efficient and practical SACs for energy, environment and sustainability. Controlling the hybridization of different metal atoms (e.g., heteroatom dimers and alloy clusters) in desirable host materials opens vast opportunities for designing and developing atomically dispersed catalysts, enabling heterogeneous catalysis at the single-atom limit.

Bio

Jingyue Liu received his bachelor’s degree in metal physics from the University of Science and Technology Beijing, China, and his PhD in condensed matter physics from ASU under the guidance of Professor John M. Cowley. He was a postdoctoral research associate and research scientist in the LeRoy-Eyring Center for Solid State Science at ASU before he joined Monsanto Corporate Research as a research specialist and group leader in 1994. After a series of promotions, he was appointed as a science fellow of Monsanto in 2000 and a senior science fellow in 2003 for sustained outstanding technical leadership and significant impacts on Monsanto’s businesses. He received the prestigious 2001 Edgar M. Queeny Award for Science and Technology, the highest award within Monsanto for scientific achievement and business impact. In 2006, he joined the University of Missouri-St. Louis as the director of the Center for Molecular Electronics and professor of Physics and Chemistry, and in 2007 became the founding director of the Center for Nanoscience. He joined ASU in 2011 as professor of physics. He became a Fellow of the Microscopy Society of America in 2012.

Seth Ariel Tongay, School for Engineering of Matter, Transport and Energy, ASU

Over the past five decades, EMC at ASU has played a pivotal role in enabling groundbreaking research on atomically thin quantum materials. These materials, which hold immense promise for next-generation electronics, quantum devices and advanced manufacturing, present significant challenges in characterization due to their extreme thinness and sensitivity. However, thanks to EMC’s world-class capabilities and expert staff, metrology on these technically challenging materials has been made not only feasible but highly effective. In this talk, we will survey key innovations made possible through EMC’s advanced characterization techniques. One of the most exciting breakthroughs involves the integration of 2D materials into diamond anvil cells, allowing us to push the boundaries of these materials under extreme high-pressure conditions. This research sheds light on phase transitions, electronic structure modifications and novel quantum phenomena that emerge under extreme environments. Additionally, we will discuss how even fundamental tasks, such as TEM sample preparation for 2D materials, once considered formidable, have been revolutionized by EMC’s technical expertise. Through precise sample handling and imaging advancements, we have gained atomic-scale insights into defects and imperfections, providing invaluable data to refine 2D material synthesis and integration strategies. By leveraging EMC’s cutting-edge metrology capabilities, we have pushed the frontiers of 2D material manufacturing, enabling new possibilities for defect engineering, heterostructure fabrication and scalable quantum material integration. This presentation will highlight how EMC’s sustained support and technological excellence have been instrumental in overcoming longstanding challenges, ultimately accelerating innovation in the field of atomically thin materials.

Bio

Seth Ariel Tongay is a renowned materials scientist specializing in materials deposition and characterization. He is an expert in EPI deposition, 2D material synthesis, and characterization to realize 2D single crystal layers and next-generation 2D semiconductors. Tongay has published over 300 journal articles and holds several patents in epitaxy domain. He has been recognized as a Highly Cited Researcher by Web of Science for six consecutive years (2019-2024). He has been recognized as an APS Fellow and Fellow of Royal Society of Chemistry (UK). He received the Presidential Early Career Award, Ten Outstanding Young Persons Award and the NSF Career Award, among other international accolades. He boasts an h-index of 83 with over 30,000 citations.

Robert Sinclair, Yi Cui and Pawel Czaja; Department of Materials Science and Engineering, Stanford University 

Since the foundational work of Cowley and Iijima, Buseck and Eyring, and many others in the 1970’s, high-resolution electron microscopy has become the essential method for directly observing the atomic arrangements in materials and devices. However, the TEM and STEM environments provide a mini laboratory for all kinds of experiments, be they physical, chemical, biological, electrochemical, etc. With the remarkable advances in such applications in parallel with inexorable development of imaging, analytical and indeed computational capabilities, it could be asked whether TEM is still useful as a “microscope” itself. This suggestion is emphatically put to rest by the example of the recent discovery of “twisted epitaxy” in metal-2D material intergrowths, which will be described in this presentation.

Bio

Robert (Bob) Sinclair is the Charles M. Pigott Professor in the School of Engineering at Stanford University. He received his degrees in materials science from Cambridge University. Following a postdoctoral position at the University of California, Berkeley, he joined the faculty in the Department of Materials Science and Engineering at Stanford in 1977. His group’s research has focused on the application of advanced transmission electron microscopy techniques, especially at high resolution, to addressing important issues in materials science, especially in the semiconductor and magnetics areas, and in medical nanotechnology. The work on in-situ high-resolution TEM and interface reactions is likely the most well known. He was department chair from 2004-2014 and director of the Stanford Nanocharacterization Laboratory for 12 years since its founding in 2002. His group’s work has been recognized by the Distinguished Scientist Award (Physical Sciences) of the Microscopy Society of America in 2009 and the David M. Turnbull Award of the Materials Research Society in 2012.

Vinayak P. Dravid, Department of Materials Science and Engineering, NUANCE Center & SHyNE Resource (an NSF-NNCI Node), Northwestern University

Characterization by scanning transmission and transmission electron microscopy is often criticized as subjective, slow and less amenable to automation. These considerations are further exacerbated under in-situ or operando conditions, which pose additional challenges of consistency, reproducibility with localized constraints and incompatibility with the “round-robin” approach. The ongoing work in our group is meant to dispel these notions. Our approach is inspired by innovations in high-throughput assays and related automation in biotech and bioinformatics.

We combine novel design and nanofabricated specimen stages with smart data acquisition strategies. It is tailored to “ration” both electrons and time, spatially and temporally, utilizing AI/ML approach and methods.

The presentation will cover emerging opportunities in advanced microscopy. It will cover innovative nanofabricated ultra-thin window fluidic cells for nanoscale discrimination of reactants and products in catalysis. The presentation will explore the feasibility of AI/ML-enabled data acquisition for rapid and high throughput materials discovery, as well as monitoring of in-situ phenomena in the temporal domain.

The local and extended ASU microscopy community has played indispensable role advancing electron microscopy across the globe for decades. I will share some historical examples and make the case for the upcoming renaissance era in electron microscopy!

Bio

Vinayak P. Dravid is the Abraham Harris Professor of Materials Science and Engineering at Northwestern University. He is the founding director of the NUANCE Center & SHyNE Resource (NSF-NNCI Center). His scholarly interests revolve around nanoscale solutions to gigaton challenges of energy and environment, utilizing microscopy and characterization methods. One of Dravid’s passions is to enhance societal and global appreciation for science and technology through the lens of microscopy and nanotechnology.=

Md Ashiqur RahmanLaskar

Controlling nanoscale tip-induced material removal is crucial for achieving atomic-level precision in tomographic sensing with atomic force microscopy (AFM). While advances have enabled volumetric probing of conductive features with nanometer accuracy in solid-state devices, materials, and photovoltaics, limitations in spatial resolution and volumetric sensitivity persist. This work identifies and addresses in-plane and vertical tip-sample junction leakage as sources of parasitic contrast in tomographic AFM, hindering real-space 3D reconstructions. Novel strategies are proposed to overcome these limitations. First, the contrast mechanisms analyzing nanosized conductive features are explored when confining current collection purely to in-plane transport, thus allowing reconstruction with a reduction in the overestimation of the lateral dimensions. Furthermore, an adaptive tip-sample biasing scheme is demonstrated for the mitigation of a class of artefacts induced by the high electric field inside the thin oxide when volumetrically reduced. This significantly enhances vertical sensitivity by approaching the intrinsic limits set by quantum tunneling processes, allowing detailed depth analysis in thin dielectrics. The effectiveness of these methods is showcased in tomographic reconstructions of conductive filaments in valence change memory, highlighting the potential for application in nanoelectronics devices and bulk materials and unlocking new limits for tomographic AFM.

Hsin Juei Wang

In response to growing concerns over the limited availability of cobalt sources for lithium-ion battery cathodes, this study explores a novel method for upcycling LiCoO2 (LCO) materials. Traditional approaches for LCO recycling, such as pyrometallurgy and hydrometallurgy, are known for their energy-intensive processes. Here, we propose a new direct upcycling approach that leverages the high surface area of LCO nanosheets to facilitate cobalt extraction and cation exchange. The method involves exfoliation of the LCO into nanosheets, where are then mixed with aqueous solutions to promote cation exchange. The effectiveness of cobalt extraction and its replacement by nickel is investigated using various characterization techniques, including Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and soft X-ray absorption spectroscopy. In addition, the reassembly of the nanosheets into functional cathode materials is also accomplished using heat treatment. The results show the successful synthesis of Ni-doped LCO (LiCo1-xNixO2, x = 0.11) using this approach. Moreover, Mn ion exchange into the exfoliated LCO is also investigated with the same method. This study establishes how nanosheet processing can be leveraged for recycling critical materials used in batteries and establishes a new pathway that can be used for converting LCO or low-Co materials to Ni-rich cathodes.

Md Jayed Hossain

Indium-Gallium-Zinc Oxide (IGZO) is a promising n-type semiconductor oxide, renowned for its exceptional electrical and mechanical properties, including high mobility, wide bandgap that enables transparency, as well as excellent electrical stability and flexibility. Consequently, it is emerging as a strong candidate for multiple applications including display technology, back-end-of-the-line (BEOL) compatible logic, and memories, thanks to its low thermal budget and compatibility with CMOS architecture. However, being a ternary alloy IGZO has a rich multitude of phases, and a major challenge lies in the costly and complex characterization for the material screening and process control. In this work, we report on the use of conductive atomic force microscopy (C-AFM), a powerful technique for the rapid screening of electrical properties of blanket IGZO films. This is enabled by the application of computer vision algorithms to classic C-AFM data acquisition. The results indicate that major material parameters can be extracted automatically, while maintaining nanometric resolution for the electrical features. Finally, we leveraged the power of computer vision and automation offered by Phyton scripting to analyze the results obtained from the raw C-AFM images, enabling accurate and automated assessment of IGZO samples. This approach allowed us to extract key parameters such as conductive spots, highly conductive areas, coverage percentage, and average current on the sample surface.

Tengteng Tang

This research investigates vat photopolymerization (VPP) as a technique to fabricate high-performance polarizers that can encode and decode hidden optical information, vital for secure information storage and transmission. The study aims to advance both additive manufacturing and optical steganography by exploring optimal process parameters, material selections, and specific refinements to enhance anisotropic properties in polarizers. A critical aspect involves understanding how layer-based VPP influences the polarization properties of the printed structures, which is key to controlling anisotropy. The methodology focuses on optimizing VPP parameters such as layer thickness and exposure duration to precisely manage the polarization characteristics. This includes fine-tuning material compositions to achieve desired polarization effects. The research also entails a comprehensive evaluation of the mechanical properties of the polarizers to assess their durability and functionality under real-world conditions. By utilizing the advanced optical characterization equipment at the Eyring Materials Center and applying these advanced polarizers in optical steganography, the project evaluates their effectiveness in securely transmitting and storing data. This has significant implications for data protection in cybersecurity, defense, and financial services, enhancing the security of information handling.

Leah Shteynman

Impact cratering creates micro-  and nano-structures in minerals that make up target rocks. These structures can record information about the cratering event, including about its timing, peak pressures and temperatures, and post-cratering processes. This project explores shock metamorphic textures in the mineral zircon, one of the most important minerals in Earth’s crust for geochemical investigations. Specifically, two microstructures related to impact cratering are targeted: (1) the high pressure polymorph reidite and (2) the  granular neoblastic texture. We use SEM, TEM, and STEM techniques in order to elucidate their mechanism(s) of formation, which have implications for these microstructures’ utility for tracking impact processes.

Marko Milosavljevic

This work examines the presence of epilayer tilt in coherently strained InAsSbBi epilayers grown on GaSb substrates that are (100) on-axis and (100) offcut 1° to [011] and (100) offcut 4° to [011].  The measurements are performed using x-ray diffraction, and consist of angle area maps in the [011] and [0-1-1] directions and coupled scans in the [011], [0-11], [01-1], and [0-1-1] directions.  The sample cross-section consists of a 500 nm GaSb buffer, a 10 nm InAs/10 nm AlSb barrier, the InAsSbBi active region, and a terminating 10 nm AlSb/10 nm InAs barrier/cap layer.  The lattice planes of strained epilayers grown on offcut substrates tilt relative to the substrate offcut plane to accommodate the in-surface biaxial-strain and the out-of-surface distortion.  Under tensile strain the epilayers tilt in the [011] direction and under compressive strain the epilayers tilt in the opposite [0-1-1] direction.  Because of the presence of crystallographic tilt, the InAsSbBi layers are examined using symmetric (400) X-ray diffraction scans and angle area maps.  The out-of-plane distortion is determined from coupled scans in the [0-11] and [01-1] directions, which are orthogonal to the epilayer tilt.  The tilt angle is proportional to tetragonal distortion and the tangent of the offcut angle.  The crystallographic tilt and the out-of-plane distortion results in an InAsSbBi unit cell that is triclinic when the offcut is in the high symmetry [011] direction, rather than tetragonal for on-axis growth.  In addition to the out-of-plane tilt that is clearly observable, the boundary conditions of coherently strained growth on a stepped surface indicate the presence of roughly the same in-plane tilt.  At the step edge, coherent growth is constrained in two directions: 1) out-of-plane along the (011) step edge and 2) in-the-plane on the (100) terrace surface.  Since the epilayer is constrained in two dimensions, it distorts both out-of-plane and in-plane with the distortion increasing as the growth progresses away from the corner of the step edge.  This results in a triclinic unit cell that is tilted both out-of-plane and in-plane.  Expressions are derived and compared with experiment for the InAsSbBi layer tilt angles, lattice constants, and angles of the triclinic unit cell.  

Yifan Wang

The main factor limiting interpretation of electron energy-loss spectroscopic (EELS) dataset collected by scanning transmission electron microscopes (STEM) is the signal-to-noise ratio (SNR). One of the most effective approaches that can improve dose efficiency is denoising. We developed the unsupervised deep video denoiser (UDVD), which was successfully applied to low dose in situ TEM movies. Here, we appied the UDVD on EELS dataset, revealing information under heavy noise.

Patrick Hays

InSeI is a quasi-1D layered semiconductor that possesses a direct band gap (Eg ≈ in its bulk form, which is retained down to the “single-chain” limit. The material is composed of alternating left- and right-handed chiral InSeI chains held together by vdW forces. InSeI is also stable under ambient conditions, making it an attractive alternative to the many organic chiral materials currently available for optoelectronic applications. However, the defect genome of InSeI has not been thoroughly studied. In this report, we investigate a unique form of stacking defect observed in InSeI using HAADF-STEM, which is deemed a “one-dimensional stacking fault”. Structure models were created and used to perform STEM simulations to better understand the nature of this defect. Furthermore, high-pressure high-temperature synthesis of InSeI was conducted inside a multi-anvil cell in an attempt to modify the global stacking order of InSeI chains. Efforts to understand the structural, optical, and electronic properties of the resulting phase of InSeI are detailed here and compared with those of the ambient pressure InSeI phase.

Priyanka Jatindra Desai

Rigid metallic surgical hardware, a gold standard in bone fracture treatment for over a century, continues to burden the healthcare system with serious adverse events that include infection, pain, impingement, migration, and mechanical failure which significantly increase healthcare costs. With substantial progress in regenerative engineered biomaterials and tissue engineering methodologies, it may now be possible to develop tunable, non-metallic, internal fixation devices utilizing advanced biomaterial composite designs that can improve patient outcomes. This study reports on the synthesis and processing of a robust sol-gel derived hydroxyapatite (HA) conformal implant coatings for next generation bone fixation surgical hardware applications. Among the various sol-gel coating techniques, dip coating possesses several advantages. This includes its ability to produce highly uniform coatings, its versatility in coating substrates having net shaped complex geometries, ability to produce uniform coatings of single and multiple layers, inherent flexibility, simplicity, and cost-effectiveness. However, the formation of sol-gel derived high-quality HA coatings are influenced by multiple experimental factors, necessitating a multi-factorial design of experiment (DOE) approach. This includes the identification of key control factors and levels crucial for producing high-quality HA coatings. The DOE approach taken herein led to the establishment of optimum dip coating processing conditions to produce mechanically robust HA coatings for next-generation non-metallic orthopaedic implant applications.

Blake Povilus

Janus transition metal dichalcogenide monolayers exhibit unique optoelectronic properties, resulting from their broken mirror symmetry and intrinsic out-of-plane dipole moments, which distinguish them from their conventional counterparts. Despite many valuable theoretical studies, experimental characterization of the optical dielectric function of Janus TMDs remains scarce. In this work, normal-incidence reflectance and Kramers-Kronig constrained analysis are used to experimentally determine the complex optical dielectric function of excitonic SeMoS and SeWS monolayers. These results reveal the presence of excitonic resonances, band nesting features, and notable spin-orbit coupling effects. Additionally, we investigate the change in the dielectric function across partially converted Janus samples, demonstrating further tunability in their optoelectronic properties. These findings provide a fundamental platform for understanding the optical response of Janus TMDs.

Melike Erdi

Chiral materials possess distinct structural and quantum properties, with InSeI emerging as a promising topologically trivial insulator. This study introduces a scalable Bridgman growth method to produce large, stable InSeI single crystals. It highlights the polarization-dependent optical and vibrational properties of InSeI chiral chains. Structural analysis confirms its chiral nature, while electron energy loss spectroscopy identifies a 2.08 eV bandgap. Angle-resolved Raman spectroscopy reveals five distinct vibrational regions, contributing to a deeper understanding of chiral material systems.

Mohammed Sahal

Solid-state batteries (SSBs) go beyond the limits of lithium-ion batteries (LiBs), delivering nearly twice the energy density (~500 Wh·kg⁻¹, ~1200 Wh·L⁻¹), five times lower self-discharge (≪2–5% per month) for enhanced storage stability, and a lifespan exceeding 3000 cycles. Additionally, by eliminating toxic, flammable electrolytes and preventing thermal runaway, SSBs provide a safer and more reliable solution for energy storage.

However, unlike LiBs, where liquid electrolytes naturally ensure efficient contact with porous electrodes, SSBs require precise control of the electrode-electrolyte interface and densification for effective contact and ion transport. This introduces complexity in manufacturing, involving high-temperature sintering, pressure-assisted consolidation, moisture management, and thermal stabilization of electrodes and electrolytes.

Current SSB manufacturing techniques are limited in their ability to integrate these additional steps for efficient cost-effective large-scale in-line fabrication. They typically rely on: (i) prolonged vacuum-based hot pressing or sintering of brittle pellets, or (ii) costly, slow, and non-scalable vacuum-based deposition methods. In contrast, integrating slurry-based large-area thin-film deposition techniques, such as spin and blade coating, with open-air plasma processing for in-line high-temperature sintering and advanced moisture management offers a practical, scalable, and cost-effective solution to the challenges faced by existing methods.
In this study, we demonstrate that open-air plasma treatment (i) enhances interface resistance and electrode contact by reducing surface contamination (e.g., Li₂CO₃) in solid electrolyte LLZO, (ii) ultra-fast functionalization of slurry-deposited LLZO thin-film electrolytes, and (iii) high-temperature sintering of the solid electrolyte LiPON. These improvements are validated using advanced materials characterization techniques, including Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS), and Powder X-ray Diffraction (XRD).

Soyeon Ko

A lithium/sulfur (Li/S) battery is one of the most promising next-generation rechargeable batteries due to its high theoretical specific energy (2600 Wh/kg vs. ~550 Wh/kg for conventional lithium-ion batteries). However, low electrical conductivity of sulfur and the problematic “lithium polysulfide (Li-PS) shuttle effect” occurring in the organic liquid electrolyte result in substantial performance degradation, preventing the commercialization of Li/S batteries. To tackle these challenges, earlier studies have focused on the modification of sulfur cathode by encapsulating elemental sulfur into nano-sized pores of porous carbon material. This approach aims to enhance the electronic conductivity of sulfur cathode and physically restrict the diffusion pathway of Li-PS. Although the performance of sulfur-porous carbon cathodes has been enhanced, there remains a need for further advancements to improve their electrochemical performance, specifically in enhancing the capture of Li-PS. This study aims to develop an innovative active material design which effectively mitigates the Li-PS shuttle effect by employing a multi-functional sulfonated metal-organic polyhedral (SMOP, [Cp3Zr3O(OH)3]4[BDC]6[(C2H5)2NH2]2Cl6]) that functions both as a sulfur confinement agent and a polysulfide immobilizer.[3] Mesoporous hallow carbon sphere (HCS) is chosen as the host material of the sulfur-HCS-MOP (S-HCS-SMOP) composite, which features a distinctive morphology and chemical structure, including elemental sulfur and SMOP nano-confined within HCS. SMOP has modified from the nano-sized discrete cage of Zr-based MOP, which is chemically stable material under electrochemical reaction, and successfully introduced to the S-HCS composite to prepare the S-HCS-SMOP. Consequently, the combination of carbon-host composite and nano-sized polysulfide immobilizer against the Li-PS shuttle is expected to enhance electrochemical performance of sulfur cathodes for Li/S batteries. These characteristics are thoroughly examined using advanced electron microscopy and spectroscopy techniques. The S-HCS-SMOP cathode successfully demonstrated improved capacity retention compared to both conventional S-porous carbon and S-HCS composite cathodes. Our results offer significant insights into the utilization of functionalized metal-organic materials for the development of high-performance lithium/sulfur cells, marking a notable contribution to the field.

Gabriela De Los Reyes Castillo

The iron and steel industry accounts for approximately 7% of global CO2 emissions. The ore reduction is traditionally carried out by a carbothermic multi-step process that generates CO2 as a byproduct, which contributes to global warming caused by greenhouse emissions and raises economic concerns. A more sustainable alternative is the implementation of Hydrogen Plasma to carry out the reduction process. Plasma is a state of matter where gas is ionized, creating a mix of positively and negatively charged electrons. Atomic, ionic, and vibrationally excited hydrogen species are present in this state, which can carry out the reduction efficiently and at low temperatures by creating localized heating, unlike the volumetric heating that is required with hydrogen in the molecular form. There are multiple reasons to use hydrogen plasma, as it offers both thermodynamic advantages and enhanced reaction kinetics, leading to a faster rate of the reduction compared to conventional methods. Additionally, it has environmental benefits, as the process produces H2O instead of CO2, eliminating harmful emissions and reducing the footprint of steel production. H2 Plasma reduction also eliminates the need for metallurgical coke and intermediate processing steps by switching to direct steelmaking, where liquid steel is obtained directly from the iron ore, bringing a reduction of energy consumption.

Triston Vo

Artificially stacked layers of transition metal dichalcogenides (TMDs) have gained significant interest in recent years due to their unique correlated properties such as unconventional superconductivity, and topological effects which can be controlled by changing the relative lattice parameters and twist angle. Mechanical exfoliation allows clean, large monolayers that are free from defects to be isolated. There are many challenges when creating a twisted structure due to the difficulty of identifying monolayers, deterministically stacking them, controlling the twist angle, and understanding their structural orientation. In this poster we go through the process of creating twisted homo and hetero-bilayers. We utilize a matlab based GUI that plots the intensity profiles of the flakes and the substrate of an RGB image to identify the number of layers. Using a custom built “transfer” station that has precision controlled x-y-z-r manipulators,we are able to transfer the monolayers from a substrate onto a target substrate or a TEM grid with success. The rotation stage on this transfer station helps us to align the two different layers together. Aligning the samples to smaller twist angles (∼1°) can be achieved by techniques such as the tear and stack method and leveraging the way crystals fracture to our advantage. By utilizing these techniques, we have fabricated twisted homo and hetero-bilayers.

Anacleto Proietti

Gallium Nitride (GaN) has emerged as a revolutionary semiconductor, enabling breakthroughs in high-frequency and high-power electronics. Its wide bandgap, high electron mobility, and strong breakdown field make it a critical material for applications demanding efficiency, speed, and thermal stability. GaN offers significant advantages for power electronics, 5G communication, and automotive systems, compared to silicon (Si) and silicon carbide (SiC). However, structural and electronic defects strongly affect the performance and reliability of AlGaN/GaN heterostructures. In this study, defects in an AlGaN/GaN heterostructure grown on SiC are analyzed using a multiscale characterization approach. Strain variations and defect-induced recombination are revealed by Raman spectroscopy and photoluminescence while Scanning Electron Microscopy identify hexagonal V-pits associated with threading dislocations and EDX confirms their deep penetration into the structure. Furthermore conductive atomic force microscopy (C-AFM) reveals leakage currents along the defect edges, and scalpel C-AFM reveals buried conductive dislocations suggesting a huge impact of these on the general electrical behaviour. Indeed, trapped charges and the 3D morphology of defects are further detected and imaged by scanning microwave impedance microscopy (sMIM). These results underscore the critical impact of defects on device performance and highlight the need for advanced nanoscale characterization to improve GaN-based electronics.

Srijan Chakrabarti

The reliability and performance of advanced electronic packaging hinge on the precise identification of microscale defects. To have a well-rounded analysis of these defects we have presented a correlative workflow including White Light Interferometry (WLI), X-ray tomography (XRT), Small Angle X-ray Scattering (SAXS), X-ray Photoelectron Spectroscopy (XPS), and Plasma Focused Ion Beam (PFIB) analysis provide a holistic view of material integrity and defect characterization. This workflow complements a non-destructive metrology method called Scanning Acoustic Microscopy (SAM). For a more accurate experimental setup we have used a finite element method called CIVA which numerically solves ultrasonic wave interaction with materials and voids. The work we present here highlights key parameters such as frequency, probe depth, resolution, and working distance which require parametric optimization through CIVA. Preliminary results from A, B, and C scans from simulation reveal critical insights into wave propagation phenomena and the interaction of high-frequency acoustic waves with void defects. These findings not only validate the proposed correlative microscopy workflow but also underscore the potential of high-frequency SAM (ranging from 400 MHz to 1 GHz) as an indispensable tool for the non-destructive evaluation of advanced packaging. Future work will extend these studies with even higher frequency transducers to further refine the detection capabilities and simulation accuracy.

Sakib Ahmed

One of the interesting failure analysis techniques is to implement magnetic current imaging, requiring high spatial resolution with excellent magnetic field sensitivity. To ensure ultra-high spatial resolution and magnetic field sensitivity with non-perturbative approach, quantum sensing with nitrogen-vacancy (NV) centers in diamond has been proven to be a strong magnetic microscopy technique, known as Scanning Nitrogen-Vacancy Magnetometry (SNVM). Along with an optical confocal microscope and a microwave (MW) antenna, the NV center can be excited through green laser and the optical readout to evaluate external magnetic field. Recently, this configuration has been implemented to demonstrate non-perturbative probing of magnetic inhomogeneities in Ni and CoFeB nanowires with sensitivities down to a few µT.Hz-1/2. With the implementation of efficient laser and MW pulsing sequences it is possible to dramatically improve the sensitivity of magnetic field measurement.