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As a critical component of coherent X-ray diffraction imaging (CDI), phase retrieval has been extensively applied in X-ray structural science to recover the 3D morphological information inside measured particles. Despite meeting all the oversampling requirements of Sayre and Shannon, current phase retrieval approaches still have trouble achieving a unique inversion of experimental data in the presence of noise. Here, we propose to overcome this limitation by incorporating a 3D Machine Learning (ML) model combining (optional) supervised learning with transfer learning. The trained ML model can rapidly provide an immediate result with high accuracy which could benefit real-time experiments, and the predicted result can be further refined with transfer learning. More significantly, the proposed ML model can be used without any prior training to learn the missing phases of an image based on minimization of an appropriate ‘loss function’ alone. We demonstrate significantly improved performance with experimental Bragg CDI data over traditional iterative phase retrieval algorithms.

Palladium absorbs large volumetric quantities of hydrogen at room temperature and ambient pressure, making the palladium hydride system a promising candidate for hydrogen storage. Here, we use Bragg coherent diffraction imaging to map the strain associated with defects in three dimensions before and during the hydride phase transformation of an individual octahedral palladium nanoparticle, synthesized using a seed-mediated approach. The displacement distribution imaging unveils the location of the seed nanoparticle in the final nanocrystal. By comparing our experimental results with a finite-element model, we verify that the seed nanoparticle causes a characteristic displacement distribution of the larger nanocrystal. During the hydrogen exposure, the hydride phase is predominantly formed on one tip of the octahedra, where there is a high number of lower coordinated Pd atoms. Our experimental and theoretical results provide an unambiguous method for future structure optimization of seed-mediated nanoparticle growth and in the design of palladium-based hydrogen storage systems. Palladium can absorb high volumes of hydrogen, but the morphology and 3D displacements occurring during palladium hydride phase formation are not fully characterized in the literature. Here, the authors use Bragg coherent diffraction imaging to map the strain within an individual palladium nanoparticle before and during hydride phase transformation, identifying a characteristic displacement caused by the seed particle in the nanocrystal.

Focused ion beam (FIB) techniques are commonly used to machine, analyse and image materials at the micro- and nanoscale. However, FIB modifies the integrity of the sample by creating defects that cause lattice distortions. Methods have been developed to reduce FIB-induced strain, however these protocols need to be evaluated for their effectiveness. Here we use non-destructive Bragg coherent X-ray diffraction imaging to study the in situ annealing of FIB-milled gold microcrystals. We simultaneously measure two non-collinear reflections for two different crystals during a single annealing cycle, demonstrating the ability to reliably track the location of multiple Bragg peaks during thermal annealing. The thermal lattice expansion of each crystal is used to calculate the local temperature. This is compared to thermocouple readings, which are shown to be substantially affected by thermal resistance. To evaluate the annealing process, we analyse each reflection by considering facet area evolution, cross-correlation maps of displacement field and binarised morphology, and average strain plots. The crystal's strain and morphology evolve with increasing temperature, which is likely to be caused by the diffusion of gallium in gold below ~280{\deg}C and the self-diffusion of gold above ~280{\deg}C. The majority of FIB-induced strains are removed by 380-410\degree C, depending on which reflection is being considered. Our observations highlight the importance of measuring multiple reflections to unambiguously interpret material behaviour., Comment: 51 pages, 16 figures

Corrosion is a major concern for many industries, as corrosive environments can induce structural and morphological changes that lead to material dissolution and accelerate material failure. The progression of corrosion depends on nanoscale morphology, stress, and defects present. Experimentally monitoring this complex interplay is challenging. Here we implement in situ Bragg coherent X-ray diffraction imaging (BCDI) to probe the dissolution of a Co–Fe alloy microcrystal exposed to hydrochloric acid (HCl). By measuring five Bragg reflections from a single isolated microcrystal at ambient conditions, we compare the full three-dimensional (3D) strain state before corrosion and the strain along the [111] direction throughout the corrosion process. We find that the strained surface layer of the crystal dissolves to leave a progressively less strained surface. Interestingly, the average strain closer to the centre of the crystal increases during the corrosion process. We determine the localised corrosion rate from BCDI data, revealing the preferential dissolution of facets more exposed to the acid stream, highlighting an experimental geometry effect. These results bring new perspectives to understanding the interplay between crystal strain, morphology, and corrosion; a prerequisite for the design of more corrosion-resistant materials.

Lithium uptake and release in lithium titanate (LTO) anode materials during a discharge and charge cycle is one of the fundamental processes of a lithium-ion battery (LIB), still not fully understood at the microscopic level. During the discharge cycle, LTO undergoes a phase transformation between Li4Ti5O12 and Li7Ti5O12 states within a cubic crystal lattice. To reveal the details of the microscopic mechanism, it is necessary to track the sequence of phase transformations at different discharge/charge states under operating conditions. Here, we use in situ Bragg coherent diffraction imaging (BCDI) and in situ X-ray diffraction (XRD) experiments to examine the lithium insertion-induced materials phase transformation within a single LTO particle and a bulk battery analogue, respectively. BCDI analysis from (111) Bragg peak shows the two-phase transformation manifesting as a distinct image phase modulation within a single LTO nanoparticle occurring in the middle of the discharge region then subsiding toward the end of the discharge cycle. We observe the biggest phase variation at the two-phase stage, indicating the formation of phase domains of 200 nm in size during the discharge process. We also observe a lattice contraction of >0.2% in a single LTO nanoparticle at the (400) Bragg peak measurement, larger than that in the corresponding bulk material. Our observation of this phase transformation at a single-particle level has implications for the understanding of the microscopic/mesoscale picture of the phase transformation in anode and cathode LIBs materials.

Fundamental understanding of structural changes during catalytic reactions is crucial to understanding the underlying mechanisms and optimizing efficiencies. Surface energy and related catalytic mechanisms are widely studied. However, the catalyst lattice deformation induced by catalytic processes is not well understood. Here, we study the strain in an individual platinum (Pt) nanoparticle (NP) using Bragg coherent diffraction imaging under in situ oxidation and reduction reactions. When Pt NPs are exposed to H

Purpose This study aims to explore the effects of consumer resilience and brand familiarity on the relationship between corporate social responsibility (CSR) and consumer attitudes toward the company conducting CSR in places that have suffered from traumatic events such as natural or anthropogenic disasters and uncertainty of public health issue. Design/methodology/approach This study collected survey-based data from 194 participants who suffered from natural and anthropogenic disasters in the state of Texas. Path analysis was used to test each structural relationship among variables after verifying the reliability and validity of each variable. Analysis of variance was used to investigate the difference in resilience between the two groups. Findings This study verified that there is a positive relationship between CSR and consumer attitude. More importantly, the results show that both resilience and familiarity play an important role as a mediator in the relationship between CSR and attitudes. In particular, it tells us that a group with high resilience shows a higher possibility of having positive attitudes toward the company than another group having low resilience. Originality/value This study empirically tested the impacts of CSR, resilience and brand familiarity on building consumer attitudes. Furthermore, this study explored the effects of resilience and brand familiarity on the relationship between CSR and attitudes. Thus, this study was able to contribute to understanding the effects of CSR, resilience and familiarity on building a positive attitude in the specific settings, in terms of traumatic events, theoretically and practically.

Understanding catalysts strain dynamic behaviours is crucial for the development of cost-effective, efficient, stable and long-lasting catalysts. Here, we reveal in situ three-dimensional strain evolution of single gold nanocrystals during a catalytic CO oxidation reaction under operando conditions with coherent X-ray diffractive imaging. We report direct observation of anisotropic strain dynamics at the nanoscale, where identically crystallographically-oriented facets are qualitatively differently affected by strain leading to preferential active sites formation. Interestingly, the single nanoparticle elastic energy landscape, which we map with attojoule precision, depends on heating versus cooling cycles. The hysteresis observed at the single particle level is following the normal/inverse hysteresis loops of the catalytic performances. This approach opens a powerful avenue for studying, at the single particle level, catalytic nanomaterials and deactivation processes under operando conditions that will enable profound insights into nanoscale catalytic mechanisms., Direct visualisation of site-specific strain variations of catalysts is needed to better understand catalytic properties. Here, the authors determine with attojoule precision that the well-known catalytic hysteresis phenomenon occurs at single particle level and involves three-dimensional strain field.

Summary Halide perovskites have emerged as a new class of inorganic-based soft semiconductors that are revolutionizing the field of (opto)electronics. However, the fundamental structures and properties or functions of halide perovskites are still far from being fully understood, calling for the need of precise, quantitative, and high-spatiotemporal-resolution characterizations. As one of the most powerful multimodal characterization techniques, synchrotron radiation offers high-brilliance X-ray beams for high-resolution observations across multiple length scales obtained within extremely short time spans. Performing a brief review of synchrotron-based perovskite studies in the literature, here we provide perspectives on the use of synchrotron characterizations not only for studying multiple-length-scale structures and dynamic variations of perovskite materials, but also for in situ monitoring of device functions and dynamics. The goal of this perspective is to present many capabilities and evoke emerging opportunities of synchrotron characterizations for providing decisive answers to the outstanding science problems in the perovskite field, pushing forward the technological development.

Strain and interactions at grain boundaries during solid-phase crystallization are known to play a significant role in the functional properties of polycrystalline materials. However, elucidating three-dimensional nanoscale grain morphology, kinetics, and strain under realistic conditions is challenging. Here, we image a single-grain growth during the amorphous-to-polycrystalline transition in technologically relevant transparent conductive oxide (TCO) film of In2O3:Zr with in-situ Bragg coherent X-ray diffraction imaging and transmission electron microscopy. We find that the Johnson-Mehl-Avrami-Kolmogorov theory, which describes the average kinetics of polycrystalline films growth, can be applied to the single grains as well. The quantitative analysis stems directly from imaging results. We elucidate the interface-controlled nature of the single-grain growth in thin films and reveal the surface strains which may be a driving force for anisotropic crystallization rates. Our results bring in-situ imaging with coherent X-rays towards understanding and controlling the crystallization processes of TCOs and other polycrystalline materials at the nanoscale.

Oxidation of magnetite (Fe3O4) has broad implications in geochemistry, environmental science and materials science. Spatially resolving strain fields and defect evolution during oxidation of magnetite provides further insight into its reaction mechanisms. Here we show that the morphology and internal strain distributions within individual nano-sized (~400 nm) magnetite crystals can be visualized using Bragg coherent diffractive imaging (BCDI). Oxidative dissolution in acidic solutions leads to increases in the magnitude and heterogeneity of internal strains. This heterogeneous strain likely results from lattice distortion caused by Fe(II) diffusion that leads to the observed domains of increasing compressive and tensile strains. In contrast, strain evolution is less pronounced during magnetite oxidation at elevated temperature in air. These results demonstrate that oxidative dissolution of magnetite can induce a rich array of strain and defect structures, which could be an important factor that contributes to the high reactivity observed on magnetite particles in aqueous environment., Oxidation of magnetite has broad implications in geochemistry and environmental science, but its reaction mechanisms are not fully understood yet. Here the authors use Bragg coherent diffractive imaging to show oxidative dissolution of magnetite inducing a rich array of strain and defect structures.

In the last two decades, Bragg Coherent X-ray Diffraction Imaging (BCDI) has become a powerful nanoscale characterization technique [1]. Its extreme sensitivity to lattice displacements enables to image three-dimensional morphology as well as internal deformation field distribution of nano- or micro-scaled various materials. In-situ and operando capabilities have been combined to BCDI to address scientific questions on materials under realistic conditions. Nowadays, in-situ/operando BCDI on electrochemistry successfully shows strain evolution and dislocation dynamics inside materials. In this talk, I will introduce current state-of-the-art of BCDI and the 34-ID-C beamline in the Advanced Photon Source which is dedicated to BCDI. This talk will also cover recent experimental results on in-situ/operando BCDI, for example, electrochemical dissolution/deposition [2] and battery materials during charging/discharging cycles [3,4]. [1] M. A. Pfeifer, et al., Nature 442, 63 (2006). [2] Y. Liu, et al., Nano Lett. 17, 1595 (2017). [3] A. Ulvestad, et al., Science 348, 1344 (2015). [4] A. Singer, et al., Nat. Energy 3, 641 (2018).

Non-equilibrium defects often dictate macroscopic functional properties of materials. In intercalation hosts, widely used in rechargeable batteries, high-dimensional defects largely define reversibility and kinetics. However, transient defects briefly appearing during ionic transport have been challenging to capture, limiting the understanding of their life cycle and impact. Here, we overcome this challenge and track operando the interaction and impact of metastable defects within NaxNi1-xMnyO2 intercalation hosts in a charging sodium-ion battery. Three-dimensional coherent X-ray imaging reveals transformation and self-healing of a metastable domain boundary, glissile dislocation loop, and stacking fault. A local strain gradient suggests a quantifiable difference in ion diffusion, coincident with the macroscopic change in diffusion coefficient. Analysis of the unexpected defect anisotropy highlights the importance of mesostructure, suggesting a possible control approach and disputing the rigidity of the framework layers. The shared nature of oxygen framework layers makes our results applicable to a wide range of intercalation materials.

Li- and Mn-rich (LMR) cathode materials that utilize both cation and anion redox can yield substantial increases in battery energy density

Alloy catalysts such as Pt-M (M: other metal elements) have been extensively developed to improve the sluggish oxygen reduction reaction (ORR) that limits the efficiencies of fuel cells and metal-air batteries. Their catalytic activity is potentially enhanced by strain induced in a nearly pure Pt "shell" formed by dissolving the alloyed metal (M) from the surface. It is, therefore, of great importance to reveal the strain distribution on the Pt shell in situ so that we can exploit this mechanism to design new alloy catalysts. Yet, it has been challenging to analyze the strain on the shell because it inevitably requires a technique that can image the strain field of the nanoparticles with high spatial resolution. In this study,1 we successfully revealed the strain of the exemplary Pt-Ni alloy nanoparticles in detail from the 3D images obtained by using a novel synchrotron technique, “Bragg Coherent X-ray Diffraction Imaging” (BCDI), which can directly image minute atomic displacement field owing to the X-ray coherence. Pt-Ni nanoparticles with compositions of Pt2Ni3 (Ni rich), Pt1Ni1 (moderate Ni), and Pt3Ni2 (Ni poor) were observed by BCDI during cyclic voltammetry cycles, in which the less noble metal Ni electrochemically leached from the alloy. This cycling induced tensile strain inside particles in all the compositions, implying that the formation of a Pt shell on the surface strained the core of the particle because of the lattice mismatch between the Pt-Ni alloys and Pt. The strain in the shell was evaluated from a core-shell elastic model using the parameters obtained in the 3D images. A compressive circumferential strain in the shell was observed in all the compositions, and the Pt1Ni1 particle showed the largest compressive circumferential strain of 5%. Since the compressive strain is reported to facilitate the enhanced ORR,2 the compositional dependence of the strain magnitude observed in this study was in excellent agreement with the previous study performed with nm-size particles where Pt1Ni1 exhibits the highest activity among a wide range of compositions.3 A similar strain-activity relation was also inferred in a powder X-ray diffraction studies of core-shell Pt x Co1-x alloys,4 suggesting it is a widely applicable phenomenon. The present study demonstrated that the strain on alloy nanoparticles can be quantitatively determined by BCDI during electrochemical reactions, which enables us to exploit surface strain in designing a wide range of electrocatalysts. T. Kawaguchi et al., Nano Letters, 21, 5945–5951 (2021). H. Wang et al., Science, 354, 1031–1036 (2016). C. Wang et al., Advanced Functional Materials, 21, 147–152 (2011). D. Wang et al., Nature Materials, 12, 81–87 (2013).

In this work, ferroelastic domain walls inside ${\mathrm{BaTiO}}_{3}$ (BTO) tetragonal nanocrystals are distinguished by Bragg peak position and studied with Bragg coherent x-ray diffraction imaging (BCDI). Convergence-related features of the BCDI method for strongly phased objects are reported. A ferroelastic domain wall inside a BTO crystal has been tracked and imaged across the tetragonal-cubic phase transition and proves to be reversible. The linear relationship of relative displacement between two twin domains with temperature is measured and shows a different slope for heating and cooling, while the tetragonality reproduces well over temperature changes in both directions. An edge dislocation is also observed and found to annihilate when heating the crystal close to the phase transition temperature.

Palladium absorbs large volumetric quantities of hydrogen at room temperature and ambient pressure, making the Pd-H system a promising candidate for hydrogen storage. Here, we use Bragg coherent diffraction imaging to map the strain associated with defects in three dimensions before and during the hydride phase transformation of an individual octahedral palladium nanoparticle, synthesized by using the seed-mediated approach. The displacement distribution imaging unveils the location of the seed nanoparticle in the final nanocrystal. By comparing our experimental results with a finite-element model, we verify that the seed nanoparticle causes a characteristic displacement distribution of the larger nanocrystal. During the hydrogen exposure, the hydride phase is predominantly formed on one tip of the octahedra, where there is a high number of lower coordinated Pd atoms. Our experimental and theoretical results provide an unambiguous method for future structure optimization of seed-mediated nanoparticles growth and in the design of palladium-based hydrogen storage systems.

The search for batteries with high energy density has highlighted lithium-rich manganese-based layered oxides due to their exceptionally high capacity. Although it is clear that both cationic and anionic redox are present in the charge compensation mechanism, the microstructural evolution of the Li2MnO3-like phase during anionic redox and its role in battery performance and structural stability are still not fully understood. Here, we systematically probe microstructural evolution using spatially resolved synchrotron X-ray measurements and reveal an underlying interaction between the Li2MnO3-like domains and bulk rhombohedral structure. Mn ion activation and a previously unobserved structural distortion are discovered at high voltages, and can be related to structural strain present in the Li2MnO3-like phase upon substantial lithium ion extraction. Moreover, we elucidate a correlation between this structural distortion and irreversible phase transitions by thermally perturbing delithiated samples. These insights highlight a pathway toward achieving high capacity cathode materials required for future commercial applications.

X-ray Bragg coherent diffraction imaging (BCDI) has been demonstrated as a powerful 3D microscopy approach for the investigation of sub-micrometre-scale crystalline particles. The approach is based on the measurement of a series of coherent Bragg diffraction intensity patterns that are numerically inverted to retrieve an image of the spatial distribution of the relative phase and amplitude of the Bragg structure factor of the diffracting sample. This 3D information, which is collected through an angular rotation of the sample, is necessarily obtained in a non-orthogonal frame in Fourier space that must be eventually reconciled. To deal with this, the approach currently favored by practitioners (detailed in Part I) is to perform the entire inversion in conjugate non-orthogonal real- and Fourier-space frames, and to transform the 3D sample image into an orthogonal frame as a post-processing step for result analysis. In this article, which is a direct follow-up of Part I, two different transformation strategies are demonstrated, which enable the entire inversion procedure of the measured data set to be performed in an orthogonal frame. The new approaches described here build mathematical and numerical frameworks that apply to the cases of evenly and non-evenly sampled data along the direction of sample rotation (i.e. the rocking curve). The value of these methods is that they rely on the experimental geometry, and they incorporate significantly more information about that geometry into the design of the phase-retrieval Fourier transformation than the strategy presented in Part I. Two important outcomes are (1) that the resulting sample image is correctly interpreted in a shear-free frame and (2) physically realistic constraints of BCDI phase retrieval that are difficult to implement with current methods are easily incorporated. Computing scripts are also given to aid readers in the implementation of the proposed formalisms.

The commissioning of a movable X-ray monochromator at the 34-ID-C endstation of the Advanced Photon Source is reported. The new instrument allows indexing of nanocrystals with Laue diffraction and collecting multi-reflection BCDI data., Measurement modalities in Bragg coherent diffraction imaging (BCDI) rely on finding a signal from a single nanoscale crystal object which satisfies the Bragg condition among a large number of arbitrarily oriented nanocrystals. However, even when the signal from a single Bragg reflection with (hkl) Miller indices is found, the crystallographic axes on the retrieved three-dimensional (3D) image of the crystal remain unknown, and thus localizing in reciprocal space other Bragg reflections becomes time-consuming or requires good knowledge of the orientation of the crystal. Here, the commissioning of a movable double-bounce Si (111) monochromator at the 34-ID-C endstation of the Advanced Photon Source is reported, which aims at delivering multi-reflection BCDI as a standard tool in a single beamline instrument. The new instrument enables, through rapid switching from monochromatic to broadband (pink) beam, the use of Laue diffraction to determine crystal orientation. With a proper orientation matrix determined for the lattice, one can measure coherent diffraction patterns near multiple Bragg peaks, thus providing sufficient information to image the full strain tensor in 3D. The design, concept of operation, the developed procedures for indexing Laue patterns, and automated measuring of Bragg coherent diffraction data from multiple reflections of the same nanocrystal are discussed.

Structural symmetry breaking and recovery in condensed-matter systems are closely related to exotic physical properties such as superconductivity (SC), magnetism, spin density waves, and charge density waves (CDWs). The interplay between different order parameters is intricate and often subject to intense debate, as in the case of CDW order and superconductivity. In ${\mathrm{La}}_{1.875}{\mathrm{Ba}}_{0.125}{\mathrm{CuO}}_{4}$ (LBCO), the low-temperature structural domain walls are hypothesized as nanometer-scale pinning sites for the CDWs. Coherent x-ray diffraction techniques have been employed here to visualize the domain structures associated with these symmetry changes directly during phase transition. We have pushed Bragg coherent diffractive imaging (BCDI) into the cryogenic regime where most phase transitions in quantum materials reside. Utilizing BCDI, we image the structural evolution of LBCO microcrystal samples during the high-temperature tetragonal to low-temperature orthorhombic (LTO) phase transition. Our results show the formation of LTO domains close to the transition temperature and how the domain size decreases with temperature. The number of domains follows the secondary order parameter (or orthorhombic strain) measurement with a critical exponent that is consistent with the three-dimensional universality class.

Structural and ion-ordering phase transitions limit the viability of sodium-ion intercalation materials in grid scale battery storage by reducing their lifetime. However, the combination of phenomena in nanoparticulate electrodes creates complex behavior that is difficult to investigate, especially on the single nanoparticle scale under operating conditions. In this work, operando single-particle x-ray diffraction (oSP-XRD) is used to observe single-particle rotation, interlayer spacing, and layer misorientation in a functional sodium-ion battery. oSP-XRD is applied to Na$_{2/3}$[Ni$_{1/3}$Mn$_{2/3}$]O$_{2}$, an archetypal P2-type sodium-ion positive electrode material with the notorious P2-O2 phase transition induced by sodium (de)intercalation. It is found that during sodium extraction, the misorientation of crystalline layers inside individual particles increases before the layers suddenly align just prior to the P2-O2 transition. The increase in the long-range order coincides with an additional voltage plateau signifying a phase transition prior to the P2-O2 transition. To explain the layer alignment, a model for the phase evolution is proposed that includes a transition from localized to correlated Jahn-Teller distortions. The model is anticipated to guide further characterization and engineering of sodium-ion intercalation materials with P2-O2 type transitions. oSP-XRD therefore opens a powerful avenue for revealing complex phase behavior in heterogeneous nanoparticulate systems., Comment: 23 pages, 4 main figures, 9 supplemental figures

While corporate philanthropy has been considered a firm’s reputation management activity, less research has focused on the relationship between CEOs as the ultimate decision maker and corporate philanthropy, particularly when organizational crises occur. To fill this research gap, this study examines certain CEO characteristics (such as founder status and CEO network) and two causes of philanthropy (such as business-related philanthropy and cause-related philanthropy). This study suggests that there will be a positive relationship between these characteristics of CEOs and causes of corporate philanthropy, and organizational crises will moderate that relationship. This study contributes to a new conceptual framework to explore the relationship between CEO characteristics and different corporate philanthropic causes following organizational crises. This study discusses the scholarly suggestions of our conceptual framework and concludes with implications for future research.

Purpose The purpose of this paper is to verify the relationship between productivity and quality in the services sector. More specifically, this study investigates the relationship between productivity and customer satisfaction and its effect on a firm’s performance. In addition, this study investigates the roles of productivity and customer satisfaction in the structural relationships among variables. Design/methodology/approach A theoretical model was proposed among innovation, productivity, customer satisfaction and firm performance. A sample of 127 firms from data sets of the American Customer Satisfaction Index and COMPUSTAT was collected. To test the hypotheses, this study used ordinal least squares analysis and path analysis. Findings The findings of this study verified that a positive relationship exists between productivity and customer satisfaction and that service productivity and customer satisfaction are positively associated with a firm’s performance. In addition, customer satisfaction was found to fully mediate the relationship between productivity and a firm’s performance. Research limitations/implications This study only focused on a short period for each variable due to the difficulty of matching all the data sets used for measuring each variable, which limited the observation of the different effects of service productivity among industries. Practical implications The findings of this study suggest that managers can improve productivity without sacrificing customer satisfaction. In addition, services firms should consider innovation, productivity and customer satisfaction in a holistic way because all of these affect a firm’s performance. Furthermore, services firms need to pay more attention to customer satisfaction, which plays an important role as a mediator in increasing a firm’s performance. Originality/value This study highlights the importance of the relationship between productivity and customer satisfaction in the services sector. In particular, this study extended the theory of service productivity by Rust and Huang (2012) to explore the role of service productivity and customer satisfaction in measuring a firm’s performance.

Purpose This study explores corporate strategic orientations as important drivers of firms’ philanthropic engagement. Specifically, the purpose of this paper is to empirically examine the relationship between two broad corporate strategic orientations – domain offense (DO) and domain abandonment (DA) strategies – and the level of philanthropic engagement. Design/methodology/approach The authors propose that firms pursuing aggressive DO strategies are more likely to invest in corporate philanthropy as part of their market expansion efforts. On the contrary, firms pursuing DA strategies are less likely to invest in corporate philanthropy because of decreased slack resources, rather conservative external stakeholder expectations as well as a firm’s conscious decision to disengage with external stakeholders. Hierarchical multiple regression analysis was conducted using data from 122 publicly traded US corporations from 2008 to 2013. Findings The findings provided empirical support for a significant positive relationship between DO strategies (acquisition and strategic alliance intensity) and firms’ philanthropic engagement. However, the relationship between DA strategies (divestiture and plant/facility closing) and firms’ philanthropic engagement was not found to be significant. Overall, the findings indicated that philanthropic engagements along with carefully crafted DO strategies help firms expand their market presence. Practical implications Organizational leaders that systematically target philanthropic causes that effectively converge with important corporate strategies do benefit in the long run by achieving better brand equity and overall enhanced corporate reputation. Originality/value By empirically investigating the relationship between corporate strategic orientations and philanthropic engagement, this study contributes to the on-going scholarly discussion on the link between corporate strategies and philanthropic engagements.

Dissolution is critical to nanomaterial stability, especially for partially dealloyed nanoparticle catalysts. Unfortunately, highly active catalysts are often not stable in their reactive environments, preventing widespread application. Thus, focusing on the structure–stability relationship at the nanoscale is crucial and will likely play an important role in meeting grand challenges. Recent advances in imaging capability have come from electron, X-ray, and other techniques but tend to be limited to specific sample environments and/or two-dimensional images. Here, we report investigations into the defect-stability relationship of silver nanoparticles to voltage-induced electrochemical dissolution imaged in situ in three-dimensional detail by Bragg coherent diffractive imaging. We first determine the average dissolution kinetics by stationary probe rotating disk electrode in combination with inductively coupled plasma mass spectrometry, which allows in situ measurement of Ag+ ion formation. We then observe...

Defects can affect all aspects of a material by altering its electronic properties and controlling its chemical reactivity. At defect sites, preferential adsorption of reactants and/or formation of chemical species at active sites are observed in heterogeneous catalysis. Understanding the structural response at defect sites during catalytic reactions provides a unique opportunity to exploit defect control of nanoparticle-based catalysts. However, it remains difficult to characterize the strain and defect evolution for a single nanocrystal catalyst in situ. Here, we report Bragg coherent X-ray diffraction imaging of defect dynamics in an individual Pt nanoparticle during catalytic methane oxidation. We observed that the initially tensile strained regions of the crystal became seed points for the development of further strain and subsequent disappearance of diffraction density during oxidation reactions. Our detailed understanding of the catalytically induced deformation at the defect sites and observed reversibility during the relevant steps of the catalytic oxidation process provide important insights of defect control and engineering of heterogeneous catalysts.

Bragg coherent diffraction imaging (BCDI), a well-established technique for imaging the internal strain of nanoparticles, was used to image the internal compositional distribution of binary alloys in thermal equilibrium. The images experimentally obtained for Pd-Rh alloy nanoparticles are presented and discussed. A direct correspondence between the lattice strain and the compositional deviation is discussed with the derivation of the BCDI displacement field aided by illustrations. The correspondence suggests that the longitudinal derivative of the displacement field, the strain induced by compositional heterogeneity, can be quantitatively converted to 3D images of the compositional deviation from the particle average by using Vegard’s law. It also suggests that the transverse derivative can be qualitatively associated with the disorder of Bragg planes. The studied Pd-Rh alloy nanoparticle exhibited internal composition heterogeneity; the Rh composition tends to be high at edges and corners between facets and gradually decreases from the surface to the core of the particle.

Imaging the dynamical response of materials following ultrafast excitation can reveal energy transduction mechanisms and their dissipation pathways, as well as material stability under conditions far from equilibrium. Such dynamical behavior is challenging to characterize, especially operando at nanoscopic spatiotemporal scales. In this letter, we use X-ray coherent diffractive imaging to show that ultrafast laser excitation of a ZnO nanocrystal induces a rich set of deformation dynamics including characteristic "hard" or inhomogeneous and "soft" or homogeneous modes at different time scales, corresponding respectively to the propagation of acoustic phonons and resonant oscillation of the crystal. By integrating the 3D nanocrystal structure obtained from the ultrafast X-ray measurements with a continuum thermo-electro-mechanical finite element model, we elucidate the deformation mechanisms following laser excitation, in particular, a torsional mode that generates a 50% greater electric potential gradient than that resulting from the flexural mode. Understanding of the time-dependence of these mechanisms on ultrafast scales has significant implications for development of new materials for nanoscale power generation.

We synthesized a planar pDPPTTi-OD polymer based on diketopyrrolopyrrole (DPP) and thieno [2,3- b ]thiophene (TTi) and investigated the electrical properties of the pDPPTTi-OD polymer. pDPPTTi-OD films displayed a low optical bandgap of 1.57 eV, and HOMO and LUMO levels of −5.40 and −3.74 eV, respectively. The 150°C-annealed pDPPTTi-OD films showed a high hole mobility of 0.16 cm 2 V −1 s −1 in organic thin-film transistor (OTFT) devices. The photovoltaic properties of polymer solar cells (PSCs) incorporating the pDPPTTi-OD were also measured. A pDPPTTi-OD:PC 71 BM blend film was spin-coated at 25, 70 and 90 °C. High-temperature processing significantly improved the power conversion efficiency of PSCs by effectively reducing the PC 71 BM domain sizes, which improved the miscibility between pDPPTTi-OD and PC 71 BM. This work demonstrated that the TTi moiety is a useful donor building block for high- performance D–A type polymers in OTFTs and PSCs, and that processing temperatures should be controlled to fully realize the materials' beneficial intrinsic properties.