Synchrotron Radiation-based Techniques Research Articles

Insights into the Performance Enhancement of Co and Mn Doped LiNiO2 Cathodes Using Synchrotron Techniques

High nickel materials, particularly LiNiO2 (LNO) with energy densities >200 mAh/g, are promising candidates and have attracted considerable interest as cathode materials for a new generation of energy storage devices [1]. However, LNO faces challenges related to low thermal stability and capacity degradation during cycling. To address these issues, several strategies have been employed, including bulk morphology modifications, electrolyte engineering, and the incorporation of metals such as Mn, Co, and Mg [2]. Doping has been identified as an effective approach to mitigate anisotropic variations in lattice parameters during cycling, thereby reducing capacity fading, improving electrochemical performance, structural and thermal stability [3]. Previous research has concluded that certain dopants are necessary to stabilize LNO cathodes over long-term cycling. Cobalt, manganese and aluminum can improve surface stability and reduce oxidative decomposition of the electrolyte. Furthermore, manganese can suppress phase transitions and contribute to higher structural stability [4]. Nonetheless, there is a significant gap in our understanding of many factors that affect the electrochemical performance of LNO cathodes.We are exploring Co and Mn doped LNO cathodes using advanced synchrotron radiation-based techniques. Using X-ray absorption spectroscopy, the X-ray absorption near edge structure (XANES) reveals the change of oxidation states as a function of the state of charge (SoC) and demonstrates stable electrochemical reversibility for LiNi0.95Co0.05O2 (NC). Notably, the edge energy positions remain stable in discharged states for NC and LiNi0.95Mn0.05O2 (NM). The extended X-ray absorption fine structure (EXAFS) provides insights into the local atomic bonding and coordination of the transition metal of interest. EXAFS reveals that Co stabilizes the local structure even with long-term cycling. Furthermore, combining X-ray transmission with spectroscopy (TXM-XANES) enables detailed chemical and morphological studies of LNO across several SoCs through both operando and post-mortem characterization. LNO, NC and NM cathodes show spherical-shape morphology, and LNO and NC cathodes show crack formation after the first charge. The edge energy positions remain consistent within the electrode with no local (interparticle) heterogeneity, but there is noticeable variation between pristine and charged cathodes. Complementary to this, we are studying the cathode-electrolyte interface (CEI) using laser ablation mass spectroscopy. By analyzing the Li content and other CEI species during charging, we observe significant electrolyte decomposition resulting in the formation of a dense CEI layer [5,6]. Although this layer is initially unstable, it stabilizes after several charge/discharge cycles. Our work provides insight into the challenges of high-energy density, high-nickel cathode design and enhanced cathode performance attributed to the dopants influence.

Beam Effects in Synchrotron Radiation Based Operando Characterization of Battery Materials: XRD and XAS Study of LiNi0.33Mn0.33Co0.33O2 and LiFePO4 Electrodes

Operando synchrotron radiation-based characterization techniques applied to energy storage materials are becoming a widespread characterization tool as they allow for non-destructive probing of materials with various depth sensitivities through spectroscopy, scattering, and imaging techniques. Moreover, they allow for faster acquisition rates, variable penetration depths, higher spectral or spatial resolution, or access to techniques that are only possible with a continuous tuneable source over a wide photon energy range. Compatibility between the electrochemical cell designs and the experimental setups may force some specific design features and care must be taken to ensure that these do not perturb the electrochemical response of the materials under investigation. The use of operando techniques has intrinsic advantages, as they enable the detection of metastable intermediates, if any, and ensure characterization under real conditions avoiding the risk of ex situ sample evolution during its preparation. However, they do not come with the extent of risks. The interaction between synchrotron radiation and samples, particularly within the intricate milieu of an operational electrochemical cell, can induce unexpected effects in the sample at the measurement spot, thereby jeopardizing the experiment's reliability and biasing data interpretation. While beam-induced effects are well-recognized for their critical impact on characterizing biological samples, macromolecules, or soft matter, they have, until recently, received scant attention within the battery research community, being vaguely referenced and incompletely understood. With the aim of contributing to this ongoing debate, a systematic investigation into these phenomena was carried out conducting a root cause analysis of beam-induced effects during the operando characterization of two commercially employed positive electrode materials: LiNi0.33Mn0.33Co0.33O2 and LiFePO4. The study spans across diverse experimental conditions involving various cell types, absorption and scattering techniques and seeks to correlate beam effects with factors such as radiation energy, photon flux, exposure time, and other parameters associated with radiation dosage. As a conclusion, a set of guidelines and recommendations are provided to evaluate and mitigate beam-induced effects that can affect the outcome of battery operando experiments.

Advanced Analytical Techniques for Characterizing Petroleum-Derived Contaminants in the Environment

The characterization of petroleum-derived contaminants in the environment is crucial for understanding their impact on ecosystems and human health. Traditional analytical techniques such as Gas Chromatography (GC), Mass Spectrometry (MS), and High-Performance Liquid Chromatography (HPLC) have been instrumental in identifying and quantifying these contaminants. However, the complexity and diversity of petroleum-derived compounds necessitate the development and application of advanced analytical techniques for more comprehensive analysis. This paper reviews the most cutting-edge methods currently employed in environmental analysis, including Comprehensive Two-Dimensional Gas Chromatography (GC×GC), Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS), Nuclear Magnetic Resonance (NMR) Spectroscopy, and Synchrotron Radiation-Based Techniques such as X-ray Absorption Spectroscopy (XAS) and X-ray Fluorescence (XRF), as well as Laser-Induced Breakdown Spectroscopy (LIBS). Each technique's principles, capabilities, and applications are discussed, highlighting their roles in detecting and characterizing hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and volatile organic compounds (VOCs). Case studies demonstrate the practical applications of these advanced techniques in real-world scenarios, such as oil spill analysis and the identification of complex contaminant mixtures. The paper also addresses the advantages and limitations of these advanced techniques, considering factors like sensitivity, selectivity, complexity, and cost. Finally, future directions and emerging technologies, including nanotechnology, biosensors, and machine learning, are explored for their potential to enhance environmental monitoring and remediation efforts. This comprehensive review underscores the importance of continued innovation in analytical methods to effectively address the challenges posed by petroleum-derived contaminants in the environment.

Beam Effects in Synchrotron Radiation Operando Characterization of Battery Materials: X-Ray Diffraction and Absorption Study of LiNi0.33Mn0.33Co0.33O2 and LiFePO4 Electrodes.

Operando synchrotron radiation-based techniques are a precious tool in battery research, as they enable the detection of metastable intermediates and ensure characterization under realistic cycling conditions. However, they do not come exempt of risks. The interaction between synchrotron radiation and samples, particularly within an active electrochemical cell, can induce relevant effects at the irradiated spot, potentially jeopardizing the experiment's reliability and biasing data interpretation. With the aim of contributing to this ongoing debate, a systematic investigation into these phenomena was carried out by conducting a root cause analysis of beam-induced effects during the operando characterization of two of the most commonly employed positive electrode materials in commercial Li-ion batteries: LiNi0.33Mn0.33Co0.33O2 and LiFePO4. The study spans across diverse experimental conditions involving different cell types and absorption and scattering techniques and seeks to correlate beam effects with factors such as radiation energy, photon flux, exposure time, and other parameters associated with radiation dosage. Finally, it provides a comprehensive set of guidelines and recommendations for assessing and mitigating beam-induced effects that may affect the outcome of battery operando experiments.

Non-Destructive and Non-Invasive Approaches for the Identification of Hydroxy Lead-Calcium Phosphate Solid Solutions ((PbxCa1-x)5(PO4)3OH) in Cultural Heritage Materials.

Lead-calcium phosphates are unusual compounds sometimes found in different kinds of cultural heritage objects. Structural and physicochemical properties of this family of materials, which fall into the hydroxypyromorphite-hydroxyapatite solid solution, or (PbxCa1-x)5(PO4)3OH, have received considerable attention during the last few decades for promising applications in different fields of environmental and material sciences, but their diagnostic implications in the cultural heritage context have been poorly explored. This paper aims to provide a clearer understanding of the relationship between compositional and structural properties of the peculiar series of (PbxCa1-x)5(PO4)3OH solid solutions and to determine key markers for their proper non-destructive and non-invasive identification in cultural heritage samples and objects. For this purpose, a systematic study of powders and paint mock-ups made up of commercial and in-house synthesized (PbxCa1-x)5(PO4)3OH compounds with a different Pb2+/Ca2+ ratio was carried out via a multi-technique approach based on scanning electron microscopy, synchrotron radiation-based X-ray techniques, i.e., X-ray powder diffraction and X-ray absorption near edge structure spectroscopy at the Ca K- and P K-edges, and vibrational spectroscopy methods, i.e., micro-Raman and Fourier transform infrared spectroscopy. The spectral modifications observed in the hydroxypyromorphite-hydroxyapatite solid solution series are discussed, by assessing the advantages and disadvantages of the proposed techniques and by providing reference data and optimized approaches for future non-destructive and non-invasive applications to study cultural heritage objects and samples.

Comprehensive study of nanostructured Bi2Te3 thermoelectric materials - insights from synchrotron radiation XRD, XAFS, and XRF techniques.

In this contribution, a comprehensive study of nanostructured Bi2Te3 (BT) thermoelectric material was performed using a combination of synchrotron radiation-based techniques such as XAFS, and XRF, along with some other laboratory techniques such as XRD, XPS, FESEM, and HRTEM. This study aims to track the change in morphological, compositional, average and local/electronic structures of Bi2Te3 of two different phases; nanostructure (thin film) and nanopowders (NPs). Bi2Te3 nanomaterial was fabricated as pellets using zone melting process in a one step process, while Bi2Te3 thin film was deposited on sodalime glass substrate using a vacuum thermal evaporation technique. Synchrotron radiation-based Bi LIII-edge fluorescence-mode X-ray absorption fine structure (XAFS) technique was performed to probe locally the electronic and fine structures of BT thin film around the Bi atom, while transmission-mode XAFS was used for BT NPs distributed in the PVP matrix. The structural features of the collected Bi LIII XANES spectra of thin film and powder samples of BT are compared with the simulated XANES spectrum of BT calculated using FDMNES code at 5 Å cluster size. Combining different off-line structural characterization techniques (XRD, FESEM, XPS, and HRTEM), along with those of synchrotron radiation-based techniques (XAFS and XRF) is necessary for complementary and supported average crystal, chemical, morphological and local electronic structural analyses for unveiling the variation between Bi2Te3 in the nanostructure/thin film and nanopowder morphology, and then connecting between the structural features and functions of BT in two different morphologies. After that, we measured the Seebeck coefficient and the power factor values for both the BT nanopowder and thin film.

Histidine- and glycine-functionalized cerium oxide nanoparticles: Physicochemical properties and antiviral activity

Cerium oxide nanoparticles (CeNPs) show great promise in biomedical applications such as theranostics of various diseases, including viral infection. In this work, we synthesized bare, histidine- and glycine-functionalized CeNPs sols and characterized them using DLS, TEM and AFM imaging, synchrotron radiation-based techniques (XPS, RPES, NEXAFS). Toxicity and antiviral activity of CeNPs were evaluated using two cell lines (mouse fibroblasts L929 and monkey kidney epithelial cells MA-104) and three types of enveloped viruses (vesicular stomatitis virus VSV, bovine beta coronavirus BCoV-1 and herpes simplex virus HSV-1/2) in vitro. The obtained data indicate the absence of toxic effects up to the maximum concentrations of CeNPs (0.05 M), wherein the growth-stimulating action was shown for all samples. A dose-dependent antiviral effect of CeNPs was demonstrated. The effect was the most pronounced for VSV, which enters the cell by endocytosis and triggers fusion at low pH. The histidine-functionalized CeNPs were the most stable and had enhanced ability to reduce the viral cytopathic effect; their therapeutic index for VSV was >50 to 1000 depending on cell type. An attempt was made to explain the observed phenomena from the point of view of the physics of the synthesized particles and the biology of the virus-cell interaction.

Covalently Interlayer-Confined Organic-Inorganic Heterostructures for Aqueous Potassium Ion Supercapacitors.

Artificial assembly of organic-inorganic heterostructures for electrochemical energy storage at the molecular level is promising, but remains a great challenge. Here, a covalently interlayer-confined organic (polyaniline [PANI])-inorganic (MoS2 ) hybrid with a dual charge-storage mechanism is developed for boosting the reaction kinetics of supercapacitors. Systematic characterizations reveal that PANI induces a partial phase transition from the 2H to 1T phases of MoS2 , expands the interlayer spacing of MoS2 , and increases the hydrophilicity. More in-depth insights from the synchrotron radiation-based X-ray technique illustrate that the covalent grafting of PANI to MoS2 induces the formation of MoN bonds and unsaturated Mo sites, leading to increased active sites. Theoretical analysis reveals that the covalent assembly facilitates cross-layer electron transfer and decreases the diffusion barrier of K+ ions, which favors reaction kinetics. The resultant hybrid material exhibits high specific capacitance and good rate capability. This design provides an effective strategy to develop organic-inorganic heterostructures for superior K-ion storage. The K-ion storage mechanism concerning the reversible insertion/extraction upon charge/discharge is revealed through ex situ X-ray photoelectron spectroscopy.

(Keynote) Dynamics in Prussian Blue Analogs-Based Batteries Revealed By X-Ray Techniques

A key factor for the developing of post-lithium batteries is represented by suitable active materials to be used in the positive and the negative electrodes. Host nanostructured have insertion sites, channels and/or interlayer spacings allowing the rapid insertion and extraction of the required ions, occurring generally with little lattice strain, with concomitant reduction/oxidation of an active metal belonging to the host. In this context Prussian Blue Analogs (PBA) offer an interesting host material for a wide variety of cations, which is also characterized by an appropriate electroactive bimetallic network.Dynamic processes occurring in batteries can be studied by operando modality, which provide a realistic representation of the electrochemical reactions occurring at the electrodes, or in ex situ modality, which reflect a given state of charge (SOC) of the electrode material. Monitoring the local structure around the metallic sites as well as the periodic structure can be performed using spectroscopic methods and in particular X-rays. X-ray absorption spectroscopy (XAS) is a synchrotron radiation-based technique that provide both electronic and structural information on a selected atomic species in a sample. General guidelines are presented in order to give a useful guide for a correct interpretation of the EXAFS spectra of this class of compounds, which is characterized by close, but sufficiently separated, discontinuities of the absorption coefficient due to contiguous transition metal K-edges. The dynamic of the ions insertion/release electrochemical reaction can further be investigated by adopting a chemometric approach using a multivariate curve resolution with alternating least squares algorithm (MCR-ALS), with the intent to assess the number of species involved and their evolutions during the electrochemical process. X-ray powder diffraction (XRPD) experiments allow monitoring the periodic structure of a material following the intercalation/release process of the ions involved. The potentiality of the joint XAS-XRD approach in the newly proposed PBA cathodes materials for rechargeable batteries is here highlighted, giving emphases on the copper hexacyanoferrate, copper nitroprusside, and manganese hexacyanoferrate electrodes.1. Conti, S. Zamponi, M. Giorgetti, M. Berrettoni, W.H. Smyrl, Anal. Chem. 82(2010)3629.2. Giorgetti, ISRN Materials Science, 2013, 938625.3. Mullaliu, M. Sougrati, N. Louvain, G. Aquilanti, M. Doublet, L. Stievano and M. Giorgetti, Electrochimica Acta 257(2017)364.4. Mullaliu, G. Aquilanti, L. Stievano, P. Conti, J. R. Plaisier, S. Cristol, and M. Giorgetti, J. Phys. Chem. C 122(2018)15868.5. Mullaliu, P. Conti, G. Aquilanti, J. Plaisier, L. Stievano, and M. Giorgetti, Condens. Matter 3(2018)36.6. Mullaliu, G. Aquilanti, P. Conti, J. R. Plaisier, M. Fehse, L. Stievano, and M. Giorgetti, J. Phys. Chem. C 123(2019)8588.7. Mullaliu, J. Asenbauer, G. Aquilanti, S. Passerini, and M. Giorgetti, Small Methods 4(2020)1900529.8. Mullaliu, G. Aquilanti, P. Conti, M. Giorgetti, and S. Passerini, ChemSusChem 13(2020) 608.9. Mullaliu, M. Gaboardi, J. R. Plaisier, S. Passerini, and M. Giorgetti, ACS Applied Energy Materials 3(2020)5728.10. Li, A. Mullaliu, S. Passerini, and M. Giorgetti, Batteries 7(2021)Art. No. 5.11. Li, R. Sciacca, M. Maisuradze, G. Aquilanti, J. Plaisier, M. Berrettoni, and M. Giorgetti, Electrochimica Acta 400(2021) Art. No. 139414.

Exploring the Antitumor Potential of Copper Complexes Based on Ester Derivatives of Bis(pyrazol-1-yl)acetate Ligands.

Bis(pyrazol-1-yl)acetic acid (HC(pz)2COOH) and bis(3,5-dimethyl-pyrazol-1-yl)acetic acid (HC(pzMe2)2COOH) were converted into the methyl ester derivatives 1 (LOMe) and 2 (L2OMe), respectively, and were used for the preparation of Cu(I) and Cu(II) complexes 3–10. The copper(II) complexes were prepared by the reaction of CuCl2·2H2O or CuBr2 with ligands 1 and 2 in methanol solution. The copper(I) complexes were prepared by the reaction of Cu[(CH3CN)4]PF6 and 1,3,5-triaza-7-phosphaadamantane (PTA) or triphenylphosphine with LOMe and L2OMe in acetonitrile solution. Synchrotron radiation-based complementary techniques (XPS, NEXAFS, and XAS) were used to investigate the electronic and molecular structures of the complexes and the local structure around copper ions in selected Cu(I) and Cu(II) coordination compounds. All Cu(I) and Cu(II) complexes showed a significant in vitro antitumor activity, proving to be more effective than the reference drug cisplatin in a panel of human cancer cell lines, and were able to overcome cisplatin resistance. Noticeably, Cu complexes appeared much more effective than cisplatin in 3D spheroid cultures. Mechanistic studies revealed that the antitumor potential did not correlate with cellular accumulation but was consistent with intracellular targeting of PDI, ER stress, and paraptotic cell death induction.

Thermal stability and protective properties of phenylphosphonic acid on Cu(111)

Phenylphosphonic acid (PPA) adsorbed on Cu(111) has been studied by synchrotron radiation-based techniques in combination with density functional theory calculations. The dehydrogenated phenylphosphonic acid molecule (PP) strongly bound in a tridentate geometry through oxygen atoms to Cu(111) is shown to be the dominant surface species in the temperature range 150–300 °C. The stable PP adlayer substantially protects the Cu(111) surface from oxidation during exposure to ambient conditions. Thermal treatment of the PPA adlayer at 375 °C initiates molecular decomposition through several channels: P–O bond scission forming C6H5PO2; C–P bond scission forming phenyl and PO3; and C–H bond scission forming C6H4PO3. All three reaction steps have activation barriers of 1.7–1.8 eV. Small products such as O, H, and phenyl can immediately react further and desorb, while the remaining phosphonate species undergo condensation. After annealing at a higher temperature, the phosphonate group is further reduced from oxygen-rich to phosphorus-rich species, which form the majority of remaining adsorbates after 500 °C treatment.

Molecular Trade-Offs between Lattice Oxygen and Oxygen Vacancy Drive Organic Pollutant Degradation in Fungal Biomineralized Exoskeletons.

Fungal-mineral interactions can effectively alleviate cellular stress from organic pollutants, the production of which are expected to rapidly increase owing to the Earth moving into an unprecedented geological epoch, the Anthropocene. The underlying mechanisms that may enable fungi to combat organic pollution during fungal-mineral interactions remain unclear. Inspired by the natural fungal sporulation process, we demonstrate for the first time that fungal biomineralization triggers the formation of an ultrathin (hundreds of nanometers thick) exoskeleton, enriched in nanosized iron (oxyhydr)oxides and biomolecules, on the hyphae. Mapped biochemical composition of this coating at a subcellular scale via high spatial resolution (down to 50 nm) synchrotron radiation-based techniques confirmed aromatic C, C-N bonds, amide carbonyl, and iron (oxyhydr)oxides as the major components of the coatings. This nanobiohybrid system appeared to impart a strong (×2) biofunctionality for fungal degradation of bisphenol A through altering molecular-level trade-offs between lattice oxygen and oxygen vacancy. Together, fungal coatings could act as "artificial spores", which enable fungi to combat physical and chemical stresses in natural environments, providing crucial insights into fungal biomineralization and coevolution of the Earth's lithosphere and biosphere.

Heavy metals concentrations and speciation of Pb and Ni in airborne particulate matter over two residential sites in Greater Cairo - reflection from synchrotron radiation.

Synchrotron radiation-based techniques [X-ray absorption near-edge structure (XANES) and X-ray fluorescence (XRF)] combined with inductively coupled plasma-mass spectrometry (ICP-MS) were used for the assessment of heavy metals concentrations as well as lead (Pb) and nickel (Ni) speciation in airborne particulate matter (PM10) over two residential sites in Greater Cairo. Nineteen 24 h high-volume samples collected at Giza (G) Square and Helwan (H) University (Egypt) were selected for this study. Mean concentrations of heavy metals in PM10 at both sites were found to have the same descending order of Pb > Cu > Ni > Cd > Co > As, of which concentrations of Pb, Cu, Ni and Cd in H samples were higher than those in G samples. For Pb, synchrotron-based XRF results were in good agreement with concentrations obtained by ICP-MS. The XANES spectra of PM10 at the Pb L2-edge and Ni K-edge were compared with those of Pb and Ni in model standard compounds to provide information on the potential oxidation states as well as the chemical forms of those elements. The data show that Pb has similar chemical environments in both series G and H with the predominance of Pb2+ oxidation state. Nickel was found as Ni(OH)2, NiO and Ni metal in the analyzed samples. However, the content of Ni in the background filter shows a very strong interference with that of the collected PM10. Carcinogenic and non-carcinogenic risks resulting from the inhalation of the studied heavy metals were assessed for children and adult residents and were found below the safe limits, at both sites.

Combination of Two Synchrotron Radiation-Based Techniques and Chemometrics to Study an Enhanced Natural Remineralization of Enamel.

The limitations to assess dental enamel remineralization have been overcome by a methodology resulting from the appropriate combination of synchrotron radiation-based techniques on both, infrared microspectroscopy and micro X-ray diffraction, with the help of specific data mining. Since amelogenin plays a key role in modulating the mineralization of tooth enamel, we propose a controlled ion release for fluorapatite structural ions (Ca2+, PO43–, and F–, also including Zn2+) by using weak acid and weak base ion-exchange resins in the presence of amelogenin to remineralize the surface of etched teeth. This combination provides the necessary ions for enamel remineralization and a guide for crystal growth due to the protein. Remineralized tooth samples were analyzed by applying the indicated methodology. The synchrotron data were treated using principal component analysis and multivariate curve resolution to analyze the mineral layer formed in the presence and absence of amelogenin. The remineralizing treatment created a fluorapatite layer free of carbonate impurities and with a similar orientation to that of the natural enamel thanks to amelogenin contribution.

Cu(I) and Cu(II) Complexes Based on Lonidamine-Conjugated Ligands Designed to Promote Synergistic Antitumor Effects.

Bis(pyrazol-1-yl)- and bis(3,5-dimethylpyrazol-1-yl)-acetates were conjugated with the 2-hydroxyethylester and 2-aminoethylamide derivatives of the antineoplastic drug lonidamine to prepare Cu(I) and Cu(II) complexes that might act through synergistic mechanisms of action due to the presence of lonidamine and copper in the same chemical entity. Synchrotron radiation-based complementary techniques [X-ray photorlectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS)] were used to characterize the electronic and molecular structures of the complexes and the local structure around the copper ion (XAFS) in selected complexes. All complexes showed significant antitumor activity, proving to be more effective than the reference drug cisplatin in a panel of human tumor cell lines, and were able to overcome oxaliplatin and multidrug resistance. Noticeably, these Cu complexes appeared much more effective than cisplatin against 3D spheroids of pancreatic PSN-1 cancer cells; among these, PPh3-containing Cu(I) complex 15 appeared to be the most promising derivative. Mechanistic studies revealed that 15 induced cancer cell death by means of an apoptosis-alternative cell death.

Optimization of magnetic properties of BaTiO3/Li0.5Fe2.5O4 multiferroics prepared via modified low-temperature combustion

Multiferroic (x)BaTiO3/(1 − x)Li0.5Fe2.5O4 (0.0 ≤ x ≤ 1) perovskite/spinel nanocomposite was synthesized using a modified citrate auto-combustion method. Both BaTiO3 (BTO) and Li0.5Fe2.5O4 (LFO) phases along with their composites were successfully characterized using X-ray diffraction, Fourier transformation infrared spectroscopy, and X-ray absorption fine structure spectroscopy. The nanoscale, morphology, and magnetic properties were imaged and acquired using high resolution transmission electron microscopy, atomic force microscopy, and vibrating sample magnetometer. Synchrotron radiation-based elemental selective XAFS technique was performed around Fe K-edge to obtain the selective and the detailed local structural information of Li0.5Fe2.5O4 nanoparticles (NPs). The main remarkable result in this work is the enhancement in the coercivity (HC) of LFO NPs after compositing with BTO particularly at x = 0.6, and at x = 0.8. Based on the collected results, BTO/LFO nanocomposite can be seen as a good candidate for different technological applications including magnetically modulated piezoelectric, safety rechargeable batteries, and multilayer ceramic capacitor.

Examining Biogenic and Diagenetic Lead Exposure with Synchrotron Radiation X-ray Fluorescence Imaging of Experimentally Altered Bone

This plain language summary summarizes research recently undertaken as part of an MA thesis (September 2020) at the Department of Archaeology and Anthropology (University of Saskatche­wan). This thesis set out to map patterns of lifetime lead exposure versus post-mortem lead contamination in bone samples from both modern Saskatchewan and archaeological individuals. In addition to measuring the lead levels of each sample, this thesis used a synchrotron radiation-based element mapping technique to map the distribution of lead within each bone sample on a microscopic scale. When lead is taken up into bone during an individual’s life, it is incorporated into actively forming bone, leading to spatial patterns that reflect individual life histories of lead exposure. When bones are contaminated by lead in the burial environment, the lead is typically found at the outer surfaces and large pores of bone. Therefore, this element mapping technique is useful in helping archaeologists distinguish between lifetime and post-mortem lead exposure and can provide important information about individual histories of lead exposure for archaeological and modern populations alike.

Characterizing the defects and ferromagnetism in metal oxides: The case of magnesium oxide

Defects play an essential role in controlling the phenomenon of d0 ferromagnetism in nonmagnetic oxides. Defects can have significant impact on behavior, especially d0 ferromagnetism of oxide materials at room temperature (RT). Defects in magnesium oxide can be created by various phenomena like ion implantation, swift heavy ion/laser/gamma or UV irradiation, etc. This review focuses on the various characterization tools that are helpful to identify the nature of defects in the materials. Microscopic studies infer about the crystal structure modification via doping concentrations in metal oxides. Tools like ultra-violet visible (UV–Vis) spectroscopy and photoluminescence (PL) spectroscopy enrich the information on defects as well as depict the kind of vacancy. Electron paramagnetic resonance (EPR) is suitable to get information on spin centers in the materials. In addition to this, synchrotron radiation-based techniques like X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) are also helpful to know about the structural defects and nature of vacancy in the materials. Vibrating sample magnetometry (VSM)/superconducting quantum interference device (SQUID) measurements deduce the magnetic properties and cause of the ferromagnetism in the metal oxide. Thus, these characterization tools are covered in this review by addressing the origin of defects as well as the methodology utilized to create and control defects in the materials. A detailed understanding of these issues is focused on magnesium oxide, a well-known candidate of the d0 ferromagnetic category.

Synchrotron Radiation-Based Micro-XANES and Micro-XRF Study of Unsuccessfully Produced Egyptian Blue from the Late Hellenistic Production Site of Kos (Dodecanese, Greece)

This paper examines the production technology of Egyptian blue, an ancient artificial pigment, through the investigation of an unsuccessfully produced pellet derived from the Hellenistic production site of Kos (Dodecanese, Greece). This heterogeneous material was investigated by a combination of laboratory and synchrotron radiation-based (SR) techniques: scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, micro-Raman spectroscopy, high-resolution SR micro-X-ray fluorescence spectroscopy, and SR micro-X-ray absorption near-edge structure spectroscopy (XANES), at the ID21 beamline of the European Synchrotron Radiation Facility. Principal component analysis of a large dataset of 171 micro-XANES spectra acquired on the archaeological samples and on a series of reference copper compounds emphasizes high variations of XANES features due to different speciation and also orientation effects, as demonstrated by the simulated XANES spectra. The results indicate that, rather than inadequate firing temperatures that could have led to the reddish cuprite (Cu2O), unsuccessful production may occur due to the use of inappropriate starting materials, which contain an unusually high iron content. The contextual interpretation underlines the intertwined relationship between the production of Egyptian blue and metallurgy.

Development of micro-Laue technique at Shanghai Synchrotron Radiation Facility for materials sciences

Synchrotron radiation-based micro-Laue technique has showcased great application potentials in materials science study for its unprecedented crystal orientation and lattice strain/stress resolution. Here we report the updated progress in the development of the micro-Laue technique on the X-ray test beamline at Shanghai Synchrotron Radiation Facility. So far, 40 µm (h) × 50 µm (v) X-ray beam spot is routinely obtained, with the convergent angle of 0.2 mrad (h) × 0.12 mrad (v). Area scans are conducted on a GH3535 Ni-based superalloy base metal and weld joint with the same chemical composition. By analyzing the tremendous amount of Laue diffraction patterns using in-house developed software packages, the crystal orientation, elastic strain, and defect distributions are mapped and investigated. Such a successful proof-of-principle study offers first-hand experience on the further optimization of the design and construction of the scanning micro-Laue facility on the superbend beamline with improved spatial resolution and multiple functions for simultaneous chemical fluorescence mapping and in-situ microstructural evolution studies. The micro-Laue diffraction beamline at Shanghai Synchrotron Radiation Facility will provide a versatile and powerful tool for the orientation and strain/stress mapping combined with phase identification with micron-sized spatial resolution.