David Shapiro

• PhD
• Staff Physicist at Lawrence Berkeley National Laboratory

We advance soft X-ray vector ptychographic tomography to map the 3D magnetization field in self-assembled superparamagnetic nanoparticles at a liquid–liquid interface, revealing how layered structures influence magnetic ordering. We observe that monolayers with low coordination numbers exhibit weak magnetic order, with magnetic vortices disrupting...

Understanding the dynamics of lithium diffusion within solid-state electrodes is pivotal for advancing high-performance batteries. Conventionally, lithium diffusion within solid-solution battery particles has been assumed to be solely driven in the direction of minimizing the concentration gradient, resulting in a monotonous lithium distribution. H...

Delithiation of layered oxide electrodes triggers irreversible oxygen loss, one of the primary degradation modes in lithium-ion batteries. However, the delithiation-dependent mechanisms of oxygen loss remain poorly understood. Here we investigate the oxygen non-stoichiometry in Li1.18–xNi0.21Mn0.53Co0.08O2–δ electrodes as a function of Li content b...

Transition-metal-based solid-state electrocatalysts undergo dynamic phase transformation governed by the local electrochemical environment during operation, e.g., oxygen evolution/reduction( 1,2 ), hydrogen evolution( 3 ), and carbon dioxide reduction( 4 ). Electrochemical active species, often hidden before operation, can become evolved due to the...

Understanding the diffusion dynamics of lithium within solid-state electrodes is pivotal for developing high-performance batteries. In this context, layered oxides were utilized as a promising cathode material due to their high energy density and fast intraparticle lithium diffusivity. Despite advancements in material composition, coating, and dopi...

Delithiation of layered oxide electrodes triggers irreversible oxygen loss, one of the primary degradation modes in lithium-ion batteries. However, the delithiation-dependent mechanisms of oxygen loss remain poorly understood. Here, we investigate the oxygen nonstoichiometry in Li- and Mn-rich Li1.18-xNi0.21Mn0.53Co0.08O2-δ electrodes as a function...

Soft x-ray coherent diffractive imaging is used to probe the fundamental scales of topological magnetic textures. 3D vector ptycho-tomography enables high resolution 3D static imaging of nanoscale spin textures in dipole-stabilized skyrmions.

Li- and Mn-rich (LMR) layered oxide positive electrode materials exhibit high energy density and have earth abundant compositions relative to conventional Ni-, Mn-, and Co-oxides (NMCs). The lithiation of coprecipitated precursors is a key part of synthesis and offers opportunities for tuning the properties of LMR materials. Whereas the morphology...

Li- and Mn-rich (LMR) layered oxide positive electrode materials exhibit high energy density and have earth abundant compositions relative to conventional Ni-, Mn-, and Co-oxides (NMCs). The lithiation of coprecipitated precursors is a key part of synthesis and offers opportunities for tuning the properties of LMR materials. Whereas the morphology...

Over 50 years of development, synchrotron based X-ray microscopy has become a routine and powerful tool for the analysis of nanoscale structure and chemistry in many areas of science. Scanning X-ray microscopy is particularly well suited to the study of chemical and magnetic states of matter and has become available at most synchrotron light source...

Topological magnetic monopoles (TMMs), also known as hedgehogs or Bloch points, are three-dimensional (3D) non-local spin textures that are robust to thermal and quantum fluctuations due to the topology protection1–4. Although TMMs have been observed in skyrmion lattices1,5, spinor Bose–Einstein condensates6,7, chiral magnets8, vortex rings2,9 and...

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Constitutive laws underlie most physical processes in nature. However, learning such equations in heterogeneous solids (for example, due to phase separation) is challenging. One such relationship is between composition and eigenstrain, which governs the chemo-mechanical expansion in solids. Here we developed a generalizable, physically constrained...

Topological magnetic monopoles, also known as hedgehogs or Bloch points, are three-dimensional (3D) nonlocal spin textures that are robust to thermal and quantum fluctuations due to their topology ¹⁻⁴ . Understanding their properties is of both fundamental interest and practical applications ¹⁻⁹ . However, it has been difficult to experimentally pr...

We developed soft x-ray vector ptychography at 10 nm spatial resolution without requiring a priori knowledge, which is then used to quantitatively image 3D magnetization vector fields of topological magnetic monopoles and their interactions.

Lithium iron phosphate (LixFePO4), a cathode material used in rechargeable Li-ion batteries, phase separates upon de/lithiation under equilibrium. The interfacial structure and chemistry within these cathode materials affects Li-ion transport, and therefore battery performance. Correlative imaging of LixFePO4 was performed using four-dimensional sc...

Single-atoms (SAs) with atomically coordinated reaction centers are considered the next generation of catalysts that can exhibit exceptional catalytic efficiency. However, the general concern about thermodynamic vulnerabilities of SAs questions their practical value. Moreover, whether the inherent catalytic nature of SAs is superior compared with t...

Scanning transmission X-ray microscopy is a powerful method for mapping chemical phases in nano-materials. The point spread function (PSF) of a conventional zone-plate-based microscope limits the achievable spatial resolution and also results in spatially resolved spectra that do not accurately reflect the spatial heterogeneity of the samples when...

Fluoride-ion batteries are an attractive energy storage concept analogous to lithium-ion batteries but feature an inverted paradigm where anions are the principal charge carriers. Insertion hosts that can reversibly insert fluoride ions at room temperature are exceedingly sparse. Here, we report that topochemical insertion of fluoride ions in FeSb2...

Constitutive laws underlie most physical processes in nature. However, learning such equations in heterogeneous solids (e.g., due to phase separation) is challenging. One such relationship is between composition and eigenstrain, which governs the chemo-mechanical expansion in solids. In this work, we developed a generalizable, physically-constraine...

Lithium iron phosphate (LixFePO4), a cathode material used in rechargeable Li-ion batteries, phase separates upon de/lithiation under equilibrium. The interfacial structure and chemistry within these cathode materials affects Li-ion transport, and therefore battery performance. Correlative imaging of LixFePO4 was performed using four-dimensional sc...

Layered oxides widely used as lithium-ion battery electrodes are designed to be cycled under conditions that avoid phase transitions. Although the desired single-phase composition ranges are well established near equilibrium, operando diffraction studies on many-particle porous electrodes have suggested phase separation during delithiation. Notably...

Increasing the energy density of layered oxide battery electrodes is challenging as accessing high states of delithiation often triggers voltage degradation and oxygen release. Here we utilize transmission-based X-ray absorption spectromicroscopy and ptychography on mechanically cross-sectioned Li1.18–xNi0.21Mn0.53Co0.08O2–δ electrodes to quantitat...

Transition metal (oxy)hydroxides are promising electrocatalysts for the oxygen evolution reaction1–3. The properties of these materials evolve dynamically and heterogeneously⁴ with applied voltage through ion insertion redox reactions, converting materials that are inactive under open circuit conditions into active electrocatalysts during operation...

Magnetic topological defects are energetically stable spin configurations characterized by symmetry breaking. Vortices and skyrmions are two well-known examples of 2D spin textures that have been actively studied for both fundamental interest and practical applications. However, experimental evidence of the 3D spin textures has been largely indirec...

A virtual special issue of Journal of Applied Crystallography brings together 14 articles from developers and practitioners in the field of ptychography, highlighting some developments in software and algorithms, instrumentation, technical requirements, and applications.

Fluorine doping of a compositionally graded cathode, with an average concentration of Li[Ni0.80Co0.05Mn0.15]O2, yields a high discharge capacity of 216 mAhg–1 with unprecedented cycling stability by retaining 78% of its initial capacity after 8,000 cycles. The cathode is cycled at 100 % depth of discharge (DOD) unlike currently deployed layered cat...

Significance Ptychography, a powerful scanning coherent diffractive imaging method, has attracted considerable attention for its general applicability. Here, we demonstrate X-ray linear dichroic ptychography to study the crystal orientations of the calcium carbonate in coral samples. In contrast to the absorption contrast commonly observed in linea...

The 3D chemical structure (4D spectromicroscopy) of nanoporous Al2O3 aerogels coated with ZnO by atomic layer deposition (ALD) was studied by multienergy scanning transmission X-ray microscopy. These materials are representative of a class of designer catalysts in which the nanoporous support is prepared separately from the active catalyst material...

The analysis of chemical states and morphology in nanomaterials is central to many areas of science. We address this need with an ultrahigh-resolution scanning transmission soft x-ray microscope. Our instrument provides multiple analysis tools in a compact assembly and can achieve few-nanometer spatial resolution and high chemical sensitivity via x...

Antidot lattices are potential candidates to act as bit patterned media for data storage as they are able to trap nanoscale magnetic domains between two adjacent holes. Here, we demonstrate the combination of micromagnetic modeling and x-ray microscopy. Detailed simulation of these systems can only be achieved by micromagnetic modeling that takes t...

Total electron yield (TEY) imaging is an established scanning transmission X-ray microscopy (STXM) technique that gives varying contrast based on a sample’s geometry, elemental composition, and electrical conductivity. However, the TEY-STXM signal is determined solely by the electrons that the beam ejects from the sample. A related technique, X-ray...

LiFePO 4 (LFP), the attractive commercial cathode materials, exhibits the phase separation between lithium-poor and lithium-rich phase within individual particles due to the wide miscibility gap. The boundaries between such phases develop large stress, lead to cracks within individual particles, and decay the cycle life. There have been lots of int...

Total electron yield (TEY) imaging is an established scanning transmission X-ray microscopy (STXM) technique that gives varying contrast based on a sample's geometry, elemental composition, and electrical conductivity. However, the TEY-STXM signal is determined solely by the electrons that the beam ejects from the sample. A related technique, X-ray...

Biominerals such as seashells, corals skeletons, bone, and enamel are optically anisotropic crystalline materials with unique nano- and micro-scale organization that translates into exceptional macroscopic mechanical properties, providing inspiration for engineering new and superior biomimetic structures. Here we use particles of Seriatopora aculea...

An energy storage paradigm orthogonal to Li-ion battery chemistries can be conceptualized by employing anions as the primary charge carriers. F-ion conversion chemistries show promise but have limited cyclability as a result of the significant change in volume of active electrodes upon metal–metal-fluoride interconversion. In contrast, the explorat...

Side reactions involving surface reduction play a critical role in the failure of LiNi0.8Co0.15Al0.05O2 to reach its theoretical capacity as a cathode material for Li-ion batteries. While macroscopic consequences are known, the underlying nanoscopic mechanisms are not fully elucidated. By coupling X-ray spectroscopy with several X-ray microscopy mo...

Highly reactive dense Pt single-atoms stabilized on an oxide support can resolve a grand challenge in the economic use of Pt in catalysis. The maximized number density of reaction sites provided by dense Pt single-atoms guarantees the improved catalytic performance of Pt combined with high efficiency. By manipulating the chemical nature of multi-co...

Multimodal microscopy that combines complementary nanoscale imaging techniques is critical for extracting comprehensive chemical, structural, and functional information, particularly for heterogeneous samples. X-ray microscopy can achieve high-resolution imaging of bulk materials with chemical, magnetic, electronic, and bond orientation contrast, w...

SQUARREL: Scattering Quotient Analysis to Retrieve the Ratio of Elements in X-ray Ptychography - Volume 25 Supplement - Chen-Ting Liao, Yuan Hung Lo, Jihan Zhou, Arjun Rana, Charles S. Bevis, Guan Gui, Bjoern Enders, Kevin Cannon, David Shapiro, Chris Bennett, Henry Kapteyn, Roger Falcone, Jianwei Miao, Margaret Murnane

Operando Scanning Transmission X-ray Microscopy of Co(OH)2 Oxygen Evolution Electrocatalysts - Volume 25 Supplement - Tyler Mefford, Khim Karki, Daan Hein Alsem, David Shapiro, Norman Salmon, William C. Chueh

Total Electron Yield Mapping of Electronic Device Features via Measurement of X-Ray Beam-Induced Currents - Volume 25 Supplement - William A. Hubbard, Jared J. Lodico, Brian Zutter, David Shapiro, Yuan Hung Lo, Arjun Rana, Drew Morrill, Christian Gentry, Ho Leung Chan, B. C. Regan

Organic photovoltaics (OPV) are a sustainable and inexpensive source of energy comprised of a mixture of an electron-donating and electron-accepting material (often a polymer and fullerene derivative respectively) to create a bulk heterojunction (BHJ). However, these devices are held back by low efficiencies. Improving the efficiency in a systemati...

During the last century, X-ray science has enabled breakthrough discoveries in fields as diverse as medicine, material science or electronics, and recently, ptychography has risen as a reference imaging technique in the field. It provides resolutions of a billionth of a meter, macroscopic field of view, or the capability to retrieve chemical or mag...

The success of ptychographic imaging experiments strongly depends on achieving high signal-to-noise ratio. This is particularly important in nanoscale imaging experiments when diffraction signals are very weak and the experiments are accompanied by significant parasitic scattering (background), outliers or correlated noise sources. It is also criti...

Dicalcium silicate (C2S) is an important clinker mineral in Portland and belite-calcium sulfoaluminate cement. However, there is still a lack of information on the local degree of silicate polymerization and calcium coordination in C2S hydration products. This study aimed to fill this gap by characterizing the hydration of two C2S polymorphs, the β...

The success of ptychographic imaging experiments strongly depends on achieving high signal-to-noise ratio. This is particularly important in nanoscale imaging experiments when diffraction signals are very weak and the experiments are accompanied by significant parasitic scattering, outliers or correlated noise sources. It is also critical when rare...

Characterizing materials at nanoscale resolution to provide new insights into structure property performance relationships continues to be a challenging research target due to the inherently low signal from small sample volumes, and is even more difficult for nonconductive materials, such as zeolites. Herein, we present the characterization of a si...

Incorporation of ions into battery electrodes can lead to phase transformations. When multiparticle phase-transforming electrodes charge or discharge, two processes must occur in each particle: the new phase must nucleate, and then grow until the particle is fully charged or discharged. A fundamental question is which of these two processes is rate...

Understanding Chemomechanical Li-ion Cathode Degradation through Multi-Scale, Multi-Modal X-ray Spectromicroscopy - Volume 24 Supplement - Sam Kalirai, Kipil Lim, Bjorn Enders, Jihyun Hong, William E. Gent, Abhas Deva, Edwin R. Garcia, Young-Sang Yu, Richard Celestre, Michael F. Toney, David A. Shapiro, William C. Chueh

The COSMIC Imaging Beamline at the Advanced Light Source: a new facility for spectro-microscopy of nano-materials - Volume 24 Supplement - David A. Shapiro, Richard Celestre, Bjoern Enders, John Joseph, Harinarayan Krishnan, Matthew A. Marcus, Kasra Nowrouzi, Howard Padmore, Jungjin Park, Anthony Warwick, Young-Sang Yu

Nanoscale Visualization of Magnetic Contrasts with Soft X-ray Spectro-Ptychography at the Advanced Light Source - Volume 24 Supplement - Young-Sang Yu, Richard Celestre, Bjoern Enders, Kasra Nowrouzi, Howard Padmore, Tony Warwick, Jong-Ryul Jeong, David A. Shapiro

Dataflow at the COSMIC Beamline - Stream Processing and Supercomputing - Volume 24 Supplement - Bjoern Enders, Kasra Nowrouzi, Harinarayan Krishnan, Stefano Marchesini, Jungjin Park, Young-Sang Yu, David A. Shapiro

The rheology of modern Portland cement (PC) concrete critically depends on the correct dosage of gypsum (calcium sulfate hydrate) to control the hydration of the most reactive phase - tricalcium aluminate (C3A). The underlying physio-chemical mechanism, however, remains unsolved mainly due to the lack of high-spatial-resolved and chemistry-sensitiv...

Polymer electrolyte membrane fuel cells (PEMFCs) are a promising and sustainable alternative to internal combustion engines for automotive applications. Polymeric perfluorosulfonic acid (PFSA) plays a key role in PEMFCs as a proton conductor in the anode and cathode catalyst layers, and in the electrolyte membrane. In this study, spectroscopic scan...

Battery function is determined by the efficiency and reversibility of the electrochemical phase transformations at solid electrodes. The microscopic tools available to study the chemical states of matter with the required spatial resolution and chemical specificity are intrinsically limited when studying complex architectures by their reliance on t...

Using Scanning Transmission X-ray Microscopy to Reveal the Origin of Lithium Compositional Spatiodynamics in Battery Materials - Volume 23 Issue S1 - Jongwoo Lim, Yiyang Li, Daan Hein Alsem, Hongyun So, Sang Chul Lee, Peng Bai, Daniel A. Cogswell, Xuzhao Liu, Norman Jin, Young-sang Yu, Norman J Salmon, David Shapiro, Martin Z Bazant, Tolek Tyliszcz...

4d Imaging of Polymer Electrolyte Membrane Fuel Cell Cathodes by Scanning X-Ray Microscopy - Volume 23 Issue S1 - Juan Wu, Adam P. Hitchcock, Mirna Lerotic, David Shapiro, Viatcheslav Berejnov, Darija Susac, Juergen Stumper

The main binding phases of calcium aluminate cement (CAC) concrete, CaO∙Al2O3∙10H2O (CAH10) and 2CaO∙Al2O3∙8H2O (C2AH8), slowly convert to 3CaO∙Al2O3∙6H2O (C3AH6) and Al(OH)3 (AH3). This reaction significantly speeds up at a temperature higher than ~30°C, and over time leads to significant strength loss in concrete. Due to the lack of direct eviden...

We present a new ptychographic x-ray microscope dedicated to soft x-ray tomography and spectromicroscopy of nano-materials at the Advanced Light Source. The microscope utilizes an ultra-stable, high performance scanning mechanism with laser interferometer feedback for sample positioning and a fast frame rate charge-coupled device detector for soft...

The Advanced Light Source has developed a compact tomographic microscope based on soft x-ray ptychography for the study of nanoscale materials [1,2]. The microscope utilizes the sample manipulator mechanism from a commercial TEM coupled with laser interferometric feedback for zone plate positioning and a fast frame rate charge-coupled device detect...

Anionic redox activity has recently been shown to be an important process that governs the electrochemical behavior of lithium-rich layered oxide electrodes. In 3d transition metal (TM) systems, it is typically believed that during the first charge this redox activity occurs via reversible depopulation of localized O2p electronic states. However, t...

We report the study of Mg cathodic electrochemical deposition on Ti and Au electrode using a multimodal approach by examining the sample area in-situ using liquid cell transmission electron microscopy (TEM), scanning transmission X-ray microscopy (STXM) and X-ray absorption spectroscopy (XAS). Magnesium Aluminum Chloride Complex was synthesized and...

The incorporation of Al and increased curing temperature promotes the crystallization and cross-linking of calcium (alumino)silicate hydrate (C-(A-)S-H), which is the primary binding phase in most contemporary concrete materials. However, the influence of Al-induced structural changes on the mechanical properties at atomistic scale is not well unde...

Precise localization of nanoparticles within a cell is crucial to the understanding of cell-particle interactions and has broad applications in nanomedicine. Here, we report a proof-of-principle experiment for imaging individual functionalized nanoparticles within a mammalian cell by correlative microscopy. Using a chemically-fixed, HeLa cell label...

We demonstrate a method for obtaining increased spatial resolution and specificity in nanoscale chemi- cal composition maps through the use of full refractive reference spectra in soft x-ray spectro-microscopy. Using soft x-ray ptychography, we measure both the absorption and refraction of x-rays through pristine reference materials as a function o...

Background The ever improving brightness of accelerator based sources is enabling novel observations and discoveries with faster frame rates, larger fields of view, higher resolution, and higher dimensionality. ResultsHere we present an integrated software/algorithmic framework designed to capitalize on high-throughput experiments through efficient...