ALBA Synchrotron Light Source

Cerdanyola del Vallès, Spain

ALBA Synchrotron Light Source

Cerdanyola del Vallès, Spain
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Arsentev M.,RAS Institute of Chemistry | Missyul A.,ALBA Synchrotron Light Source | Petrov A.V.,Saint Petersburg State University | Hammouri M.,California State Polytechnic University, Pomona
Journal of Physical Chemistry C | Year: 2017

Good cyclability is essential for the potential application of cathode materials. We investigated electrochemical properties of Mg in layered intercalation compound from first-principles using TiS3 as a model system. The calculations showed exothermic phase transformation upon intercalation of Mg from the electrolyte: the geometry optimization of the structure containing 0.5 Mg showed the shift of layers accompanied by change of Mg coordination from square pyramidal to trigonal prismatic. Further increase of the Mg content leads to break of the S-S bonds in the disulfide ion and conversion of the TiS3 layers into ribbons. The obtained phase is metastable and can easily and irreversibly decompose to MgS and TiS2. This means that in order to achieve full theoretical capacity of TiS3 this decomposition has to be suppressed. A very low migration barrier of 0.292-0.698 eV (depending on the Mg content) was found in the [010] direction, which is much lower than the value of analogues, such as layered and spinel TiS2. This finding reveals the potential of TiS3 to become Mg cathode with superior performance compared to similar analogues. © 2017 American Chemical Society.

Conesa J.J.,CSIC - National Center for Biotechnology | Oton J.,CSIC - National Center for Biotechnology | Chiappi M.,CSIC - National Center for Biotechnology | Carazo J.M.,CSIC - National Center for Biotechnology | And 4 more authors.
Scientific Reports | Year: 2016

We used soft X-ray three-dimensional imaging to quantify the mass of superparamagnetic iron oxide nanoparticles (SPION) within whole cells, by exploiting the iron oxide differential absorption contrast. Near-edge absorption soft X-ray nanotomography (NEASXT) combines whole-cell 3D structure determination at 50 nm resolution, with 3D elemental mapping and high throughput. We detected three-dimensional distribution of SPIONs within cells with 0.3 g/cm3 sensitivity, sufficient for detecting the density corresponding to a single nanoparticle.

Olivares-Marin M.,CSIC - Institute of Materials Science | Olivares-Marin M.,University of Extremadura | Sorrentino A.,ALBA Synchrotron Light Source | Pereiro E.,ALBA Synchrotron Light Source | Tonti D.,CSIC - Institute of Materials Science
Journal of Power Sources | Year: 2017

Products deposited on an O2-cathode discharged in ionic liquid electrolytes are analyzed by transmission soft X-ray microscopy (TXM) and compared to ether-based electrolytes, showing differences in morphology and chemical compositions. With both solvents we observe Li2O2 and LiO2 primary products in similar proportions. However, while as previously observed in tetraglyme an important reactivity takes place producing significant amount of carbonates, in ionic liquid-based electrolytes the formation of carbonates was almost negligible, confirming higher stability. Only when sample is intentionally air exposed before analysis, significant amounts of carbonates came up. However, LiOH crystallites are clearly recognized with the ionic liquid electrolyte. The abundance of these crystallites depends on both the LiTFSI concentration and the storage time of discharged electrodes, suggesting that they result from the reaction of water trace with primary discharge products. © 2017 Elsevier B.V.

Sorrentino A.,ALBA Synchrotron Light Source | Nicolas J.,ALBA Synchrotron Light Source | Valcarcel R.,ALBA Synchrotron Light Source | Chichon F.J.,CSIC - National Center for Biotechnology | And 6 more authors.
Journal of Synchrotron Radiation | Year: 2015

The performance of MISTRAL is reported, the soft X-ray transmission microscopy beamline at the ALBA light source (Barcelona, Spain) which is primarily dedicated to cryo soft X-ray tomography (cryo-SXT) for three-dimensional visualization of whole unstained cells at spatial resolutions down to 30 nm (half pitch). Short acquisition times allowing for high-throughput and correlative microscopy studies have promoted cryo-SXT as an emerging cellular imaging tool for structural cell biologists bridging the gap between optical and electron microscopy. In addition, the beamline offers the possibility of imaging magnetic domains in thin magnetic films that are illustrated here with an example. © 2015 International Union of Crystallography.

Oton J.,CSIC - National Center for Biotechnology | Sorzano C.O.S.,CSIC - National Center for Biotechnology | Marabini R.,Polytechnic University of Mozambique | Pereiro E.,ALBA Synchrotron Light Source | Carazo J.M.,CSIC - National Center for Biotechnology
Optics Express | Year: 2015

Soft X-ray tomography (SXT) is becoming a powerful imaging technique to analyze eukaryotic whole cells close to their native state. Central to the analysis of the quality of SXT 3D reconstruction is the estimation of the spatial resolution and Depth of Field of the X-ray microscope. In turn, the characterization of the Modulation Transfer Function (MTF) of the optical system is key to calculate both parameters. Consequently, in this work we introduce a fully automated technique to accurately estimate the transfer function of such an optical system. Our proposal is based on the preprocessing of the experimental images to obtain an estimate of the input pattern, followed by the analysis in Fourier space of multiple orders of a Siemens Star test sample, extending in this way its measured frequency range. © 2015 Optical Society of America.

Olivares-Marin M.,CSIC - Institute of Materials Science | Sorrentino A.,ALBA Synchrotron Light Source | Lee R.-C.,National Taiwan University | Pereiro E.,ALBA Synchrotron Light Source | And 2 more authors.
Nano Letters | Year: 2015

The discharge products of ether-based Li-O2 cells were grown directly on common carbon-coated TEM grids and observed by oxidation-state-sensitive full field transmission soft X-ray microscopy (TXM). The acquired data have permitted to quantify and localize with spatial resolution the distribution of the oxygen discharge products in these samples (i.e., lithium superoxide, peroxide, and carbonates) and appreciate several compositional, structural, and morphological aspects. Most of the peroxide particles had a toroidal shape, often with a central hole usually open on only one side, and which included significant amounts of superoxide-like phases (LiO2/Li2O2 ratio between 0.2 and 0.5). Smaller particles had smaller or no superoxide content, from which we infer that abundance of soluble LiO2 may have a role in toroid formation. Significant amount of carbonates were found irregularly distributed on the electrode surface, occasionally appearing as small particles and aggregates, and mostly coating lithium peroxide particles. This suggests the formation of a barrier that, similar to the solid electrolyte interface (SEI) critical in Li-ion batteries, requires an appropriate management for a reversible operation. © 2015 American Chemical Society.

Lopez-Periago A.,CSIC - Institute of Materials Science | Vallcorba O.,ALBA Synchrotron Light Source | Domingo C.,CSIC - Institute of Materials Science | Ayllon J.A.,Autonomous University of Barcelona
Crystal Growth and Design | Year: 2016

An innovative crystallization process, based on the use of the ecofriendly supercritical carbon dioxide (scCO2) solvent, is presented for the production of coordination compound macrocrystals of general formula [Cu(hfacac)2(dPy)2], with intriguing prismatic hollow structures and single polymorphic forms. In contrast, conventional solvents yielded compact microstructures. The studied pyridine derivatives (dPy) were 4-phenylpyridine, PhPy; 4-benzylylpyridine, BzPy; and 4-acetylpyridine, AcPy. In the specific case of the [Cu(hfacac)2(AcPy)2] adduct, the use of scCO2 as a solvent allowed obtaining a pure polymorph, while the conventional solvent trials yielded a mixture of two polymorphs. Four new crystalline structures have been resolved from single crystal X-ray diffraction. All the structures consist of mononuclear complexes connected through intermolecular interactions, including H⋯;H, H⋯;O, F⋯;F, C-F⋯;Caromatic, and/or C-F⋯;π interactions, generating bi-dimensional networks that determine their crystallization mode in scCO2. © 2016 American Chemical Society.

Ferrer S.,ALBA Synchrotron Light Source
Synchrotron Radiation News | Year: 2016

ALBA is the Spanish synchrotron facility located in the area of Barcelona. It is a low-emittance, 3 GeV machine having, at present, seven state-of-the-art operating beamlines covering soft and hard X-rays. The hard X-ray beamlines comprise macromolecular crystallography, non-crystalline diffraction (SAXS and WAXS), high-resolution powder diffraction, and absorption spectroscopy. The soft X-ray beamlines include a photoemission beamline with two endstations—one devoted to photoelectron microscopy (PEEM) and the second to near ambient pressure photoemission (NAPP)—and another beamline devoted to XMCD and soft X-ray scattering. Both beamlines allow full control of the polarization of the beam, since they are equipped with helical undulators. An additional soft X-ray beamline, installed on a bending magnet port, is equipped with a full-field transmission X-ray microscope. Additional information may be found at © , Copyright Taylor & Francis.

Stone K.H.,Lawrence Berkeley National Laboratory | Valvidares S.M.,ALBA Synchrotron Light Source | Kortright J.B.,Lawrence Berkeley National Laboratory
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

Resonant x-ray scattering is a powerful technique for the study of electronic structure at the nanoscale. In common practice, the optical properties of the constituent components of a material must be known prior to modeling of the scattered intensity. We present a means of refining electronic structure, in the form of optical properties, simultaneously with physical structure, in a Kramers-Kronig consistent manner. This approach constitutes a sensitive and powerful extension of resonant x-ray scattering to materials where the optical properties are not sufficiently well known. The application of this approach to specular reflectivity from a single crystal of SrTiO 3 is presented as an example case, wherein we find evidence for both a nonresonant surface contaminant layer and a modified SrTiO 3 surface region. Extrapolating from this study we comment on the potential utility of this approach to resonant scattering studies in general. © 2012 American Physical Society.

Gallego P.,Autonomous University of Barcelona | Planell R.,Autonomous University of Barcelona | Benach J.,ALBA Synchrotron Light Source | Querol E.,Autonomous University of Barcelona | And 2 more authors.
PLoS ONE | Year: 2012

The metabolism of arginine towards ATP synthesis has been considered a major source of energy for microorganisms such as Mycoplasma penetrans in anaerobic conditions. Additionally, this pathway has also been implicated in pathogenic and virulence mechanism of certain microorganisms, i.e. protection from acidic stress during infection. In this work we present the crystal structures of the three enzymes composing the gene cluster of the arginine deiminase pathway from M. penetrans: arginine deiminase (ADI), ornithine carbamoyltransferase (OTC) and carbamate kinase (CK). The arginine deiminase (ADI) structure has been refined to 2.3 Å resolution in its apo-form, displaying an "open" conformation of the active site of the enzyme in comparison to previous complex structures with substrate intermediates. The active site pocket of ADI is empty, with some of the catalytic and binding residues far from their active positions, suggesting major conformational changes upon substrate binding. Ornithine carbamoyltransferase (OTC) has been refined in two crystal forms at 2.5 Å and 2.6 Å resolution, respectively, both displaying an identical dodecameric structure with a 23-point symmetry. The dodecameric structure of OTC represents the highest level of organization in this protein family and in M.penetrans it is constituted by a novel interface between the four catalytic homotrimers. Carbamate kinase (CK) has been refined to 2.5 Å resolution and its structure is characterized by the presence of two ion sulfates in the active site, one in the carbamoyl phosphate binding site and the other in the β-phosphate ADP binding pocket of the enzyme. The CK structure also shows variations in some of the elements that regulate the catalytic activity of the enzyme. The relatively low number of metabolic pathways and the relevance in human pathogenesis of Mycoplasma penetrans places the arginine deiminase pathway enzymes as potential targets to design specific inhibitors against this human parasite. © 2012 Gallego et al.

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