X-ray synchrotron radiation studies of actinide materials

By reviewing a selection of X-ray diffraction (XRD), resonant X-ray scattering (RXS), X-ray magnetic circular dichroism (XMCD), resonant and non-resonant inelastic scattering (RIXS, NIXS), and dispersive inelastic scattering (IXS) experiments, the potential of synchrotron radiation techniques in studying lattice and electronic structure, hybridization effects, multipolar order and lattice dynamics in actinide materials is demonstrated.

Magnetic Properties and Local Structure of the (La, Co) Co-Doped Bi1−xLaxFe0.95Co0.05O3

In this study, the structural, morphological, and magnetic properties and the local structure of Bi1−xLaxFe0.95Co0.05O3 (x = 0.05, 0.10, 0.15, 0.20) nanoparticles were systematically investigated. In the (La, Co) co-doped BiFeO3 samples, a structural transition from a rhombohedral to orthorhombic structure was observed via X-ray diffraction. This structural phase transition resulted in significantly improved magnetic properties (Ms = 1.706 emu/g at 60 kOe). SEM analysis revealed that grain size decreased with increasing La concentration. The magnetic hysteresis loops confirmed that the significant enhancement of magnetization for all samples. Finally, combining the experimental synchrotron radiation techniques, we studied the samples’ local structure in order to analyze the reasons why the samples’ magnetic properties were enhanced.

Artificial laminar oxide multiferroic magnetoelectric thin film structures - Elaboration methods and study by synchrotron radiation techniques

Nanometric laminar two-dimensional artificial multiferroic oxide thin films can be elaborated using spinel ferrites and perovskite ferroelectrics like CoFe2O4 and BaTiO3. Such materials can retain their individual ferromagnetic or ferroelectric properties. In the thin epitaxial film regime a cross coupling of these properties is possible thanks to strain engineering. After introducing the concepts supporting artificial multiferroic laminar structures, the growth of strained BaTiO3 thin films and the growth of subsequent Co-ferrites layers will be detailed. With respect to the relative film thickness, a detailed understanding of the elastic behavior of these films will be proposed based on the characterization using several synchrotron radiation techniques including x-ray specular and off-specular diffraction, x-ray absorption spectroscopy, as well as x-ray magnetic circular dichroism.

Synchrotron radiation techniques in catalytic science

This themed issue includes a collection of articles on Synchrotron Radiation Techniques in Catalytic Science.

Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia)

Preserved labile tissues (e.g., skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopy to elucidate the structure of 72 million-year-old squamous (scaly) skin from a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of ∼75 microns, which is topographically and morphologically congruent with the stratum corneum in modern reptiles. Compositionally, this band deviates from that of the surrounding sedimentary matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate that carbon appears predominantly as carbonyl in the skin. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the sedimentary matrix and appear with kaolinite-rich laminae. These hosting carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite may, independently or collectively, have played important roles in the preservation of the layered structures.

Advanced Synchrotron Radiation Techniques for Nanostructured Materials

Nanostructured materials exploit physical phenomena and mechanisms that cannot be derived by simply scaling down the associated bulk structures and behaviors; furthermore, new quantum effects come into play in nanosystems [...]

Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia)

Preserved labile tissues (e.g. skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopes to elucidate the structure of 72 million-year-old squamous (scaly) skin associated with a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of 75 μm. Compositionally, this band deviates from that of the surrounding matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate the presence of carboxylic compounds. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the associated sedimentary matrix and seem associated to kaolinite. These carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite might have played important roles in the preservation of the layered structures.

Integumentary structure and composition in an exceptionally well-preserved hadrosaur (Dinosauria: Ornithischia)

Preserved labile tissues (e.g. skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopes to elucidate the structure of 72 million-year-old squamous (scaly) skin associated with a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of 75 μm. Compositionally, this band deviates from that of the surrounding matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate the presence of carboxylic compounds. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the associated sedimentary matrix and seem associated to kaolinite. These carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite might have played important roles in the preservation of the layered structures.