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BioMAX is the first macromolecular crystallography beamline at the first fourth-generation storage ring, the 3 GeV storage ring at MAX IV Laboratory. It is a highly automated, user-friendly, microfocus beamline that provides excellent performance for most macromolecular crystallography applications., BioMAX is the first macromolecular crystallography beamline at the MAX IV Laboratory 3 GeV storage ring, which is the first operational multi-bend achromat storage ring. Due to the low-emittance storage ring, BioMAX has a parallel, high-intensity X-ray beam, even when focused down to 20 µm × 5 µm using the bendable focusing mirrors. The beam is tunable in the energy range 5–25 keV using the in-vacuum undulator and the horizontally deflecting double-crystal monochromator. BioMAX is equipped with an MD3 diffractometer, an ISARA high-capacity sample changer and an EIGER 16M hybrid pixel detector. Data collection at BioMAX is controlled using the newly developed MXCuBE3 graphical user interface, and sample tracking is handled by ISPyB. The computing infrastructure includes data storage and processing both at MAX IV and the Lund University supercomputing center LUNARC. With state-of-the-art instrumentation, a high degree of automation, a user-friendly control system interface and remote operation, BioMAX provides an excellent facility for most macromolecular crystallography experiments. Serial crystallography using either a high-viscosity extruder injector or the MD3 as a fixed-target scanner is already implemented. The serial crystallography activities at MAX IV Laboratory will be further developed at the microfocus beamline MicroMAX, when it comes into operation in 2022. MicroMAX will have a 1 µm × 1 µm beam focus and a flux up to 1015 photons s−1 with main applications in serial crystallography, room-temperature structure determinations and time-resolved experiments.

On the day of the 2016 summer solstice, June 21, MAX IV, the new synchrotron radiation facility in Lund, Sweden, will be inaugurated. MAX IV is setting a new standard in terms of emittance, thereby providing beamlines with the best possible brilliance and coherence. At the same time, MAX IV continues a more than three-decades-long successful history of Swedish synchrotron-radiation-based research. The activities at the present MAX-lab, which officially started when the MAX I storage ring opened for users in 1986, have been concluded with a “last beamdump” ceremony for the MAX II and MAX III storage rings on December 13, 2015, Saint Lucy's Day. In Sweden, the winter solstice is celebrated with a festival of light.

Structural, elastic and electronic properties of zircon-type and scheelite-type EuVO4 are investigated experimentally, by in-situ X-ray diffraction using synchrotron radiation, and theoretically within the framework of the density functional theory (DFT) and using the PBE prescription of the exchange-correlation energy. This study was motivated by the fact that the previous knowledge of the equation of state (EOS) was inconclusive due to a large scatter of the experimental and theoretical data, and by the lack of information on the dependence of the electronic structure with pressure. Under the applied experimental conditions, the zircon-type structure transforms to a scheelite-type one at 7.4(2) GPa, whereas the calculations yield a lower zircon-scheelite-coexistence pressure of 4.8 GPa. The experimental part of the study shows that the bulk modulus of the zircon-type phase is 119(3) GPa, perfectly supported by the DFT-calculated value, 119.1 GPa. The bulk modulus for the scheelite-type polymorph is higher, with an experimental value of 135(7) GPa and a theoretical one of 137.4 GPa. Compared to those reported in previous experimental and DFT or semiempirical works, the present values for the zircon-type phase are comparable or slightly lower, whereas those for the scheelite-type phase are markedly lower. Discrepancies between the present results and earlier reported ones are attributed to differences in details of the experimental method such as the pressure transmitting medium and the pressure calibration method. The calculated band structure confirms that zircon-type EuVO4 is a direct-gap semiconductor, with a bandgap energy at zero pressure of 2.88 eV. Under compression, the bandgap of the zircon phase increases with a coefficient of 10.3 meV/GPa up to the transition pressure, at which point the present calculations show a small drop of the bandgap energy. Above the transition pressure, the bandgap energy of the scheelite phase becomes almost constant, with a small pressure coefficient of just 1.5 meV/GPa. (C) 2015 Elsevier B.V. All rights reserved. (Less)

A reactive hydride composite (RHC) with initial composition 3CaH 2 + 4MgB 2 + CaF 2 was studied by in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and X-ray absorption near edge structure (XANES) at the B K-edge and at the Ca K-edge. The hydrogenation reaction proceeds by an unknown intermediate. No evidence of intermediates was observed during the dehydrogenation reaction. B and Ca K-edge XANES results hint to a closed interaction of CaF 2 and Ca(BH 4) 2. The main function of CaF 2 in the 3CaH 2 + 4MgB 2 + CaF 2 RHC is as a dopant for the hydrogenation and dehydrogenation reactions. Fil: Suarez Alcantara, K.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Ramallo Lopez, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Boesenberg, U.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Saldan, I.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Pistidda, C.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Requejo, Felix Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Jensen, T.. University Aarhus; Dinamarca Fil: Cerenius, Y.. Lund University; Suecia Fil: Sørby, M.. Ife Institute for Energy Technology; Noruega Fil: Avila, J.. Synchrotron Soleil; Francia Fil: Bellosta von Colbe, J.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Taube, K.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Klassen, Thomas. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania Fil: Dornheim, M.. Helmholtz-Zentrum Geesthacht. Institute of Materials Research; Alemania

The thermal decomposition of BaC2O4 center dot 3.5H(2)O and BaC2O4 center dot 0.5H(2)O was investigated using in situ synchrotron X-ray and neutron powder diffraction. The decomposition routes for the barium oxalate hydrates were observed to depend on the applied heating rate. Thermal decomposition of BaC2O4 center dot 0.5H(2)O showed transformation to alpha-BaC2O4 and to beta-BaC2O4 prior to the formation of BaCO3. The decomposition of BaC2O4 center dot 3.5H(2)O showed formation of BaC2O4 center dot 0.5H(2)O at 58 degrees C and the hemi hydrate transforms to alpha-BaC2O4 at 187 degrees C using a relatively fast heating rate of 6.25 degrees C/min. The phase transitions were more complicated using lower heating rate, which also reveal formation of beta-BaC2O4 coexisting with alpha-BaC2O4 along with an unidentified compound. Heating alpha- and beta-BaC2O4 to higher temperatures (T > 400 degrees C) produced BaCO3. A sample of alpha-BaC2O4 was prepared in situ by thermal decomposition of BaC2O4 center dot 3.5H(2)O on a powder neutron diffractometer. The neutron diffraction data has broad diffraction peaks due to small crystallite sizes and overlapping Bragg reflections. [A structural model for alpha-BaC2O4 was derived from the neutron pattern, triclinic, space group P-1, a = 5.127(7), b = 8.905(12), c = 9.068(12) angstrom, alpha = 82.74(1), beta = 99.46(2), gamma = 100.10(1)degrees measured at T= 300 degrees C. The average Ba-O distances are 2.84(3) angstrom and 2.66(3) angstrom for Ba 1 and Ba2 respectively, C-O atom distances in the oxalate ions were found in the range 1.25(3)-1.26(4) angstrom, and C-C distances were 1.60(1)-1.61(1) angstrom]. (C) 2011 Elsevier Masson SAS. All rights reserved. (Less)

Nanoconfined 2LiBH(4)-MgH2 is prepared by direct melt infiltration of bulk 2LiBH(4)-MgH2 into an inert nanoporous resorcinol-formaldehyde carbon aerogel scaffold material. Scanning electron microscopy (SEM) micrographs and energy dispersive X-ray spectroscopy (EDS) mapping reveal homogeneous dispersion of Mg (from MgH2) and B (from LiBH4) inside the carbon aerogel scaffold. Moreover, nanoconfinement of LiBH4 in the carbon aerogel scaffold is confirmed by differential scanning calorimetry (DSC). The hydrogen desorption kinetics of the nanoconfined 2LiBH(4)-MgH2 is significantly improved as compared to bulk 2LiBH(4)-MgH2. For instance, the nanoconfined 2LiBH(4)-MgH2 releases 90% of the total hydrogen storage capacity within 90 mm, whereas the bulk material releases only 34% (at T = 425 degrees C and p(H-2) = 3.4 bar). A reversible gravimetric hydrogen storage capacity of 10.8 wt % H-2, calculated with respect to the metal hydride content, is preserved over four hydrogen release and uptake cycles. (Less)

A composite of Ca(BH4)2−MgF2 is proposed as a reversible hydrogen storage system. The dehydrogenation and rehydrogenation reaction mechanisms are investigated by in situ time-resolved synchrotron radiation powder X-ray diffraction (SR-PXD) and Raman spectroscopy. The formation of an intermediate phase (CaF2−xHx) is observed during rehydrogenation. The hydrogen content of 4.3 wt % is obtained within 4 h during the first dehydrogenation at isothermal and isobaric conditions of 330 °C and 0.5 bar H2, respectively. The cycling efficiency is evaluated by three release and uptake cycles together with absorbed hydrogen content in the range 5.1−5.8 wt % after 2.5 h (T = 330 °C and p(H2) = 130 bar). The kinetic properties on the basis of hydrogen absorption are comparable for all cycles. As compared to pure Ca(BH4)2 and Ca(BH4)2−MgH2 composite, Ca(BH4)2−MgF2 composite reveals the kinetic destabilization and the reproducibility of hydrogen storage capacities during cycling, respectively.

Complex hydrides are very promising candidates for future light-weight solid state hydrogen storage materials. The present work illustrates detailed characterization of such novel hydride materials on different size scales by the use of synchrotron radiation and neutrons. The comprehensive analysis of such data leads to a deep understanding of the ongoing processes and mechanisms. The reaction pathways during hydrogen desorption and absorption are identified by in situ X-ray diffraction (XRD). Function and size of additive phases are estimated using X-ray absorption spectroscopy (XAS) and anomalous small-angle X-ray scattering (ASAXS). The structure of the metal hydride matrix is characterized using (ultra) small-angle neutron scattering (SANS/USANS). The hydrogen distribution in tanks filled with metal hydride material is studied with neutron computerized tomography (NCT). The results obtained by the different analysis methods are summarized in a final structural model. The complementary information obtained by these different methods is essential for the understanding of the various sorption processes in light metal hydrides and hydrogen storage tanks.

The hydrogen absorption mechanism of the 2NaH + MgB2 system has been investigated in detail. Depending on the applied hydrogen pressure, different intermediate phases are observed. In the case of absorption measurements performed under 50 bar of hydrogen pressure, NaBH4 is found not to be formed directly. Instead, first an unknown phase is formed, followed upon further heating by the formation of NaMgH3 and a NaH−NaBH4 molten salt mixture; only at the end after heating to 380 °C do the reflections of the crystalline NaBH4 appear. In contrast, measurements performed at lower hydrogen pressure (5 bar of H2), but under the same temperature conditions, demonstrate that the synthesis of NaBH4 is possible without occurrence of the unknown phase and of NaMgH3. This indicates that the reaction path can be tuned by the applied hydrogen pressure. The formation of a NaH−NaBH4 molten salt mixture is observed also for the measurement performed under 5 bar of hydrogen pressure with the formation of free Mg. However, un...

Two multipurpose sample cells of quartz (SiO2) or sapphire (Al2O3) capillaries, developed for the study of solid–gas reactions in dosing or flow mode, are presented. They allow fast change of pressure up to 100 or 300 bar (1 bar = 100 000 Pa) and can also handle solid–liquid–gas studies., This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid–gas reactions in dosing or flow mode, but can also handle samples involved in solid–liquid–gas studies. The sample can be loaded into a single-crystal sapphire (Al2O3) capillary, or a quartz (SiO2) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be ∼300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to ∼100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies.

LiF-MgB2 composites are proposed for reversible hydrogen storage. With respect to pure LiBH4, a significantly kinetic destabilization regarding hydrogenation and dehydrogenation is accomplished. The reversible hydrogen storage capacity is up to 6.4 wt %. The kinetic properties are improved significantly during cycling. The formations of the hydridofluoride phases (LiBa4-yFy and LiH1-xFx) are observed by in situ synchrotron X-ray diffraction (XRD) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Hydrogenation and dehydrogenation mechanisms are described on the basis of the formation and decomposition of the hydridofluoride phases, respectively.

Synthesis and decomposition mechanisms of ternary Mg2FeH6 were investigated using in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high-pressure differential scanning calorimetry (HP-DSC). Two routes for synthesis of Mg2FeH6 were studied. The first utilizes a ball-milled homogeneous MgH2-Fe powder mixture and the second uses a mixture of Fe and Mg formed by decomposition of the ternary hydride, Mg2FeH6. In both cases the reaction mixture was sintered in a temperature range from RT to 500 degrees C under a hydrogen pressure of 100-120 bar. The reaction mechanisms were established using in-situ SR-PXD. The formation of Mg2FeH6 consists of two steps with MgH2 as an intermediate compound, and the presence of magnesium was not observed. In contrast, the decomposition of Mg2FeH6 was found to be a single-step reaction. Additionally, both reactions were investigated using HP-DSC under similar conditions as in the SR-PXD experiments in order to estimate reaction enthalpies and temperatures. Mg2FeH6 was found to form from MgH2 and Fe under hydrogen pressure regardless of whether the MgH2 was introduced in the mixture or formed prior to creation of the ternary hydride. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. (Less)

Experimental study of the phase transition in the lithium-excess lithium-manganese spinel over the pressure range 0-13 GPa has shown its suppression. This observation implies that the Li/Mn ratio, associated with the manganese oxidation state, plays an important role in the high-pressure phase transformation of the lithium-manganese spinels. As indicated by the results, the occupation of the octahedral sites with Li+ and Mn4+ ions stabilizes the crystallographic structure of this cubic spinel even at a high pressure. (C) 2009 Elsevier Ltd. All rights reserved.

Silver behenate, a salt of the behenic acid, known mostly for its applications in photothermographic imaging and use as a diffraction reference material, was studied by X-ray diffraction under pressures up to 11.4 GPa. Diffraction patterns were collected using a diamond anvil cell and synchrotron radiation at the 1711 beamline (MAXlab, Lund). The variation of the d spacing with pressure is determined and the potential usefulness of this dependence for pressure calibration is discussed. (C) 2009 Elsevier Ltd. All rights reserved.

Mix and match: A novel series of alkali-metal zinc borohydrides, LiZn 2(BH 4) 5 (see picture), NaZn 2(BH 4) 5, and NaZn(BH 4) 3, with fascinating structures are presented. An interpenetrated network structure, containing a [Zn 2(BH 4) 5] -. ion, is observed for the first time for a borohydride. A three-dimensional framework containing a polymeric [{Zn(BH 4) 3} n] n- ion is also identified. © 2009 Wiley-VCH Verlag GmbH & Co. KCaA.

LiBH4 is one of the promising candidates for hydrogen storage materials because of its high gravimetric and volumetric hydrogen capacity. However, its high dehydrogenation temperature and limited reversibility has been a hurdle for its use in real applications. In an effort to overcome this barrier and to adjust the thermal stability, we make a composite system LiBH4-Ca(BH4)(2). In order to fully characterize this composite system we study xLiBH(4) + (1 - x)Ca(BH4)(2) for several x values between 0 and 1, using differential scanning calorimetry, in situ synchrotron X-ray diffraction, thermogravimetric analysis, and mass spectrometry. Interestingly, this composite undergoes a eutectic melting at ca. 200 degrees C in a wide composition range, and the eutectic composition lies between x = 0.6 and 0.8. The decomposition characteristics and the hydrogen capacity of this composite vary with x, and the decomposition temperature is lower than both the pure LiBH4 and Ca(BH4)(2) at intermediate conpositions, for example, for x approximate to 0.4, decomposition is finished below 400 degrees C releasing about 10 wt % of hydrogen. Partial reversibility of this system was also confirmed for the first time for the case of if mixed borohydride composite.

This work demonstrates that hydrogen can be reversibly stored in a composite of NaF and Al. NaF and Al reacts to a mixture of Na3AlF6 and NaAlH4 via hydridofluoride phases of the form Na3AlH6-xFx. The analysis of thermodynamics based on literature standard enthalpies of formation yields the technically favourable enthalpy of reaction of roughly 35 kJ/mol H-2 for a theoretical gravimetric hydrogen storage capacity of 3.3 wt%. Reaction mechanisms are discussed with respect to substitution of hydrogen by fluorine in complex hydrides. (C) 2008 Elsevier B.V. All rights reserved.

At least five crystalline phases can be found in the CaSO4−H2O system, which are gypsum CaSO4·2H2O, the subhydrates α- and β-CaSO4·0.5H2O, and the soluble and insoluble anhydrite CaSO4. The formation of these five phases in the CaSO4−H2O system and their transformations were investigated by in situ time-resolved synchrotron radiation powder X-ray diffraction (SR-PXD) in this study. Furthermore, revised structural models for β-CaSO4·0.5H2O and soluble anhydrite CaSO4 are presented. The hydration of α-CaSO4·0.5H2O was studied at 25 °C and showed that the reaction with H2O started immediately after mixing the two reactants and that the formation of CaSO4·2H2O was coupled to the depletion of α-CaSO4·0.5H2O. The thermal decomposition of CaSO4·2H2O was investigated in the temperature range of 25−500 °C and showed the formation of α-CaSO4·0.5H2O followed by the formation of soluble anhydrite AIII-CaSO4, which was gradually converted to insoluble anhydrite AII-CaSO4. The thermal decomposition of α-CaSO4·0.5D2O wa...

Lithium tetrahydridoboranate is among the materials with the highest hydrogen content and has great potential as a possible H-2-storage material, although, the release and uptake of H-2 is not fully understood. In this work, LiBH4 was studied by in situ synchrotron radiation powder X-ray diffraction (PXD) and solid state CP/MAS NNIR both at variable temperatures. This study revealed two new phases observed during dehydrogenation of LiBH4. Phase I is hexagonal, a = 4.93(2) and c = 13.47(3) angstrom and is observed in the temperature range -200-300 degrees C, and phase II is orthorhombic, a = 8.70(1), b = 5.44(1) and c = 4.44](8) angstrom and is observed in the temperature range similar to 300-400 degrees C applying a constant heating rate of 5 degrees C/min. Apparently, I transforms into II, e.g. at a constant temperature of T= 265 degrees C after 5 h. Furthermore, a third phase, III, is observed in the temperature range RT to 70 degrees C, and is caused by a reaction between LiBH4 and water vapor from the atmosphere. Hydrogen release is associated with the decomposition of III at ca. 65 degrees C. (C) 2007 Elsevier B.V. All rights reserved.

A detailed analysis of the reaction mechanism of the reactive hydride composite (RHC) MgH2 + 2LiBH(4) MgB2 + 2LiH + 4H(2) was performed using high-pressure differential scanning calorimetry (HP-DSC) measurements and in situ synchrotron powder X-ray diffraction (XRD) measurements along with kinetic investigations using a Sievert-type apparatus. For the desorption the following two-step reaction has been observed: MgH2 + 2LiBH(4) Mg + 2LiBH(4) + H-2 MgB2 + 2LiH + 4H(2). However, this reaction is kinetically restricted and proceeds only at elevated temperatures. In contrast to the desorption reaction, LiBH4 and MgH2 are found to form simultaneously under fairly moderate conditions of 50 bar hydrogen pressure in the temperature range of 250-300 degrees C. As found in pure light metal hydrides, significant improvement of sorption kinetics is possible if suitable additives are used. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. (Less)

The melting temperature of alpha-silicon nitride, up to a pressure of 37 GPa, was determined by using the diamond-anvil cell technique, together with laser heating and spectroradiometry. The melting temperature varied from 2200 ± 75 K at 3.5 GPa to 3600 ± 200 K at 37 GPa; the extrapolated temperature at 1 atm was estimated to be 2100 ± 75 K.

Based on the Synchrotron Radiation (SR) beamline optical element-by-element alignment with analysis of the alignment results an optimized beamline alignment algorithm has been designed and developed. The alignment procedures have been designed and developed for the MAX-lab 1911-4 fixed energy beamline. It has been shown that the intermediate information received during the monochromator alignment stage can be used for the correction of both monochromator and mirror without the next stages of alignment of mirror, slits, sample holder, etc. Such an optimization of the beamline alignment procedures decreases the time necessary for the alignment and becomes useful and helpful in the case of any instability of the beamline optical elements, storage ring electron orbit or the wiggler insertion device. which could result in the instability of angular and positional parameters of the SR beam. A general purpose software package for manual, semi-automatic and automatic SR beamline alignment has been designed and developed using the developed algorithm. The TANGO control system is used as the middle-ware between the stand-alone beamline control applications BLTools, BPMonitor and the beamline equipment. (C) 2010 Elsevier B.V. All rights reserved.

A new X-ray crystallographic beamline is operational at the MAX II synchrotron in Lund. The beamline has been in regular use since August 1998 and is used both for macro- and small molecule diffraction as well as powder diffraction experiments. The radiation source is a 1.8 T multipole wiggler. The beam is focused vertically by a bendable mirror and horizontally by an asymmetrically cut Si(111) monochromator. The wavelength range is 0.8-1.55 A with a measured flux at 1 A of more than 10(11) photons s(-1) in 0.3 mm x 0.3 mm at the sample position. The station is currently equipped with a Mar345 imaging plate, a Bruker Smart 1000 area CCD detector and a Huber imaging-plate Guinier camera. An ADSC 210 area CCD detector is planned to be installed during 2000.

An ionizing detector for on-line registration and representation of the geometric SR beam parameters was developed in RRC KI. The detector analyses the products of the residual gas ionization, which was done by the investigated beam. Special electrostatic optics and open image converter tube (ICT) form optical image of the real beam on the screen of ICT. The detector was checked on SR beams of the next storage rings: DCI (LURE, Orsey, France), KSRS (RRC KI, Moscow, Russia) and MAX-2 (MAX-lab, Lund, Sweden). The codes for TV image processing give a possibility for numeric estimation of the beam size, the width of its horizontal and vertical profiles and position of the beam gravity. Statistic processing of the beam gravity center using big amount of TV frames gives uncertainty in the beam position of about 2 μm while the width of the beam is about 2 mm. Summation of big amount of TV frames was used. This method significantly increases signal-to-noise ratio.

The compressibility of iridium was determined by energy-dispersive X-ray diffraction and synchrotron radiation up to a pressure of 65 GPa in the diamond-anvil cell. The bulk modulus ( B 0 ) was determined to be B 0 =306 (23) with B 0 ′=6.8 (1.5) when using a third order Birch–Murnaghan equation of state (B–M EoS). A distortion in the FCC structure of iridium was seen at pressures exceeding 59 GPa as additional diffraction peaks. These could be explained by the formation of a superlattice. By assuming hexagonal settings for a closed-packed structure it was determined to be a 14-layer closed-packed structure with cell parameters: a =2.60 and c =29.7 A at 65 GPa.

International audience; Elastic properties of CaMnO3 are of primary importance in the science and technology of CaMnO3-based perovskites. From X-ray diffraction experiments performed at pressures up to 100 kbar using a diamond-anvil cell to hydrostatically compress our sample, a bulk modulus, K 0, of 1734(96) kbar was obtained after fitting parameters to the third-order Birch–Murnaghan equation of state. Mean field, semiclassical simulations predict, for the first time, the third-order equation-of-state parameters and show how the bulk modulus increases with pressure (the zero pressure value being 2062.1 kbar) and decreases with the extent of nonstoichiometry caused by the formation of oxygen vacancies. These trends are amplified for the shear modulus. A more accurate model that allows for the explicit reduction of Mn ions, or localization of excess electrons, yields qualitatively similar results. The experimental and calculated axial ratios show the same trends in their variation with rising pressure.

When becoming operational for users June 21, 2016 the MAX IV facility will be the lowest emittance synchrotron light source in the world. The low emittance gives outstanding performance regarding brightness and coherence of the synchrotron light thereby enabling entirely new science. Here we first describe the details of the new MAX IV Laboratory light sources concentrating on the low emittance 3 GeV ring. Second we describe the already funded beamline program with e.g. a 10 nm focus hard X-ray beamline, soft X-ray beamlines with very high energy resolution and photon flux, and a high-throughput macro-molecular beamline. Thirdly, we describe ongoing efforts to extend the beamline program and make full use of the outstanding properties of the radiation source.

A composite material in the LiH-LiF-MgB2 system has been synthesized by high-energy ball milling. Some peaks in addition to that of the binary 2LiH-MgB2 and 2LiF-MgB2 systems are observed for the composite material by high-pressure differential scanning calorimetry (HP-DSC), indicating the formation of intermediate phases. In situ synchrotron radiation powder X-ray diffraction (SR-PXD) performed at 60 bar of H-2 and 390 degrees C shows a superposition of both reaction pathways that are typical for 2LiH-MgB2 and 2LiF-MgB2. After hydrogen absorption of the LiH-LiF-MgB2 composite the vibrational modes of LiBH4 were observed by attenuated total reflection infrared (ATR-IR) spectroscopy. The F-19 MAS NMR spectrum of the LiF-LiBH4 sample after heat treatment in hydrogen is strongly dominated by the centerband and spinning sidebands from LiF; in addition, a low-intensity resonance, very similar to that of [BF4](-) ion, is identified. (Less)

A ternary Mg2COH5 hydride was synthesized using a novel method that relies on a relatively short mechanical milling time (1 h) of a 2:1 MgH2-Co powder mixture followed by sintering at a sufficiently high hydrogen pressure (>85 bar) and heating from RT to 500 degrees C. The ternary hydride forms in less than 2.5 h (including the milling time) with a yield of similar to 90% at similar to 300 degrees C. The mechanisms of formation and decomposition of ternary Mg2COH5 were studied in detail using an in situ synchrotron radiation powder X-ray diffraction (SR-PXD). The obtained experimental results are supported by morphological and microstructural investigations performed using SEM and high-resolution STEM. Additionally, thermal effects occurring during the desorption reaction were studied using DSC. The morphology of as-prepared ternary Mg2COH5 is characterized by the presence of porous particles with various shapes and sizes, which, in fact, are a type of nanocomposite consisting mainly of nanocrystallites with a size of similar to 5 nm. Mg2COH5 decomposes at approximately 300 degrees C to elemental Mg and Co. Additionally, at approximately 400 degrees C, MgCo is formed as precipitates inserted into the Mg Co matrix. During the rehydrogenation of the decomposed residues, prior to the formation of Mg2COH5, MgH2 appears, which confirms its key role in the synthesis of the ternary Mg2COH5. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. (Less)

Evaluation of structure and morphology of extruded wheat gluten (WG) films showed WG protein assemblies elucidated on a range of length scales from nano (4.4 angstrom and 9 to 10 angstrom, up to 70 angstrom) to micro (10 mu m). The presence of NaOH in WG films induced a tetragonal structure with unit cell parameters, a = 51.85 angstrom and c = 40.65 angstrom, whereas NH(4)OH resulted in a bidimensional hexagonal close-packed (HCP) structure with a lattice parameter of 70 angstrom. In the WG films with NH(4)OH, a highly polymerized protein pattern with intimately mixed glutenins and gliadins bounded through SH/SS interchange reactions was found. A large content of beta-sheet structures was also found in these films, and the film structure was oriented in the extrusion direction. In conclusion, this study highlights complexities of the supramolecular structures and conformations of wheat gluten polymeric proteins in biofilms not previously reported for biobased materials.

Light metal borohydrides are considered as promising materials for solid state hydrogen storage. Because of the high hydrogen content of 11.5 wt % and the rather low dehydrogenation enthalpy of 32 kJ mol−1H2, Ca(BH4)2 is considered to be one of the most interesting compounds in this class of materials. In the present work, the effect of selected TM-fluoride (TM = transition metal) additives on the reversible formation of Ca(BH4)2 was investigated by means of thermovolumetric, calorimetric, Fourier transform infrared spectroscopy, and ex situ, and in situ synchrotron radiation powder X-ray diffraction (SR-PXD) measurements. Furthermore, selected desorbed samples were analyzed by 11B{1H} solid state magic angle spinning nuclear magnetic resonance (MAS NMR). Under the conditions used in this study (145 bar H2 pressure and 350 °C), TiF4 and NbF5 were the only additives causing partial reversibility. In these two cases, 11B{1H} MAS NMR analyses detected CaB6 and likely CaB12H12 in the dehydrogenation products....

A new hydrogen absorbing material has been discovered, ScNiAl, which can store 1.5 wt.% hydrogen reversibly. In this compound, hydrogen absorption is a two-step process; solid solution of hydrogen ...

We report on an x-ray scattering experiment of bulk poly[9,9-bis(2-ethylhexyl)fluorene] under quasihydrostatic pressure from 1 to 11 GPa at room temperature. The scattering pattern of high molecular weight (HMW) polyfluorene (>10 kg/mol) undergoes significant changes between 2 and 4 GPa in the bulk phase. The 110 reflection of the hexagonal unit cell disappears, indicating a change in equatorial intermolecular order. The intensity of the 00 21 reflection drops, with a sudden move toward higher scattering angles. Beyond these pressures, the diminished 00 21 reflection tends to return toward lower angles. These changes may be interpreted as a transition from crystalline hexagonal to glassy nematic phase (perceiving order only in one direction). This transition may be rationalized by density arguments and the underlying theory of phase behavior of hairy-rod polyfluorene. Also the possible alteration of the 21-helical main chain toward more planar main chain conformation is discussed. The scattering of low molecular weight polyfluorene (

A novel aluminium rich alloy for hydrogen storage has been discovered, ScAl0.8Mg0.2, which has very promising properties regarding hydrogen storage capacity, kinetics and stability towards air oxidation in comparison to hydrogen absorption in state-of-the-art intermetallic compounds. The absorption of hydrogen was found to be very fast, even without adding any catalyst, and reversible. The discovered alloy crystallizes in a CsCl-type structure, but decomposes to ScH2 and Al(Mg) during hydrogen absorption. Detailed analysis of the hydrogen absorption in ScAl0.8Mg0.2 has been performed using in situ synchrotron radiation powder X-ray diffraction, neutron powder diffraction and quantum mechanical calculations. The results from theory and experiments are in good agreement with each other.

Due to its high hydrogen content and its favourable overall thermodynamics magnesium tetrahydroborate has been considered interesting for hydrogen storage applications. In this work we show that unsolvated amorphous magnesium tetrahydroborate can be obtained by reactive ball milling of commercial MgB2 under 100 bar hydrogen atmosphere. The material was characterized by solid-state NMR which showed the characteristic features of Mg(BH4)2, together with those of higher borohydride species. High pressure DSC and TPD-MS showed thermal behaviour similar to that of Mg(BH4)2 but with broadened signals. In situ synchrotron X-ray powder diffraction confirmed the amorphous state of the material and showed the typical crystalline decomposition products of Mg(BH4)2 at elevated temperatures.

In situ synchrotron powder X-ray diffraction (PXRD) measurements have been conducted tofollow the nucleation and growth of crystalline CexZr1-xO2 nanoparticles synthesized in supercriticalwater with a full substitution variation (x = 0, 0.2, 0.5, 0.8, and 1.0). Direction-dependent growthcurves are determined and described using reaction kinetic models. A distinct change in growthkinetics is observed with increasing cerium content. For x = 0.8 and 1.0 (high cerium content), thegrowth is initially limited by the surface reaction kinetics; however, at a size of ∼6 nm, the growthchanges and becomes limited by the diffusion of monomers toward the surface. For x=0 and 0.2, theopposite behavior is observed with the growth initially being limited by diffusion (up to∼3.5 nm) andlater by the surface reaction kinetics. Thus, although a continuous solid solution can be obtained forthe ceria-zirconia system, the growth of ceria and zirconia nanoparticles is fundamentally differentunder supercritical water conditions. For comparison, ex situ synthesis has also been performed usingan in-house supercritical flow reactor. The resulting samples were analyzed using PXRD, small-angleX-ray scattering (SAXS), and transmission electron microscopy (TEM). The nanoparticles with x=0, 0.2, and 0.5 have very low polydispersities. The sizes range from 4 nm to 7 nm, and the particlesexhibit a reversibly pH-dependent agglomeration. Udgivelsesdato: 2010

Mix and match: A novel series of alkali-metal zinc borohydrides, LiZn 2(BH 4) 5 (see picture), NaZn 2(BH 4) 5, and NaZn(BH 4) 3, with fascinating structures are presented. An interpenetrated network structure, containing a [Zn 2(BH 4) 5] -. ion, is observed for the first time for a borohydride. A three-dimensional framework containing a polymeric [{Zn(BH 4) 3} n] n- ion is also identified. © 2009 Wiley-VCH Verlag GmbH & Co. KCaA.

A novel aluminium rich alloy for hydrogen storage has been discovered, ScAl0.8Mg0.2, which has very promising properties regarding hydrogen storage capacity, kinetics and stability towards air oxidation in comparison to hydrogen absorption in state-of-the-art intermetallic compounds. The absorption of hydrogen was found to be very fast, even without adding any catalyst, and reversible. The discovered alloy crystallizes in a CsCl-type structure, but decomposes to ScH2 and Al(Mg) during hydrogen absorption. Detailed analysis of the hydrogen absorption in ScAl0.8Mg0.2 has been performed using in situ synchrotron radiation powder X-ray diffraction, neutron powder diffraction and quantum mechanical calculations. The results from theory and experiments are in good agreement with each other.

A surprisingly high degree of structural and compositional dynamics is observed in the system LiBH4−LiCl as a function of temperature and time. Rietveld refinement of synchrotron radiation powder X-ray diffraction (SR-PXD) data reveals that Cl− readily substitutes for BH4− in the structure of LiBH4. Prolonged heating a sample of LiBH4−LiCl (1:1 molar ratio) above the phase transition temperature and below the melting point (108 < T < 275 °C) can produce highly chloride substituted hexagonal lithium borohydride, h-Li(BH4)1−xClx, e.g., x ∼ 0.42, after heating from room temperature (RT) to 224 °C at 2.5 °C/min. LiCl has a higher solubility in h-LiBH4 as compared to orthorhombic lithium borohydride, o-LiBH4, which is illustrated by a LiBH4−LiCl (1:1) sample equilibrated at 245 °C for 24 days and left at RT for another 13 months. Rietveld refinement reveals that this sample contains o-Li(BH4)0.91Cl0.09 and LiCl. This illustrates a significantly faster dissolution of LiCl in h-LiBH4 as compared to a slower segr...

At least five crystalline phases can be found in the CaSO4-H2O system, which are gypsum CaSO4 · 2H2O, the subhydrates R- and � -CaSO4 · 0.5H2O, and the soluble and insoluble anhydrite CaSO4. The formation of these five phases in the CaSO4-H2O system and their transformations were investigated by in situ time-resolved synchrotron radiation powder X-ray diffraction (SR-PXD) in this study. Furthermore, revised structural models for � -CaSO4 · 0.5H2O and soluble anhydrite CaSO4 are presented. The hydration of R-CaSO4 · 0.5H2O was studied at 25 °C and showed that the reaction with H2O started immediately after mixing the two reactants and that the formation of CaSO4 · 2H2O was coupled to the depletion of R-CaSO4 · 0.5H2O. The thermal decomposition of CaSO4 · 2H2O was investigated in the temperature range of 25-500 °C and showed the formation of R-CaSO4 · 0.5H2O followed by the formation of soluble anhydrite AIII-CaSO4, which was gradually converted to insoluble anhydrite AII-CaSO4. The thermal decomposition of R-CaSO4 · 0.5D2O was investigated in the temperature range of 25-500 °C and showed successive phase transformations to � -CaSO4 · 0.5D2O, soluble anhydrite AIII-CaSO4, and insoluble anhydrite AII-CaSO4. The two polymorphs of anhydrite coexist in the investigated temperature range of 200-500 °C. The hydrothermal decomposition of CaSO4 · 2H2O was investigated in the temperature range of 25-200 °C usin ga1MH NO 3 or a1M LiCl solution, and in both experiments, CaSO4 · 2H2O was converted to R-CaSO4 · 0.5H2O and further to insoluble anhydrite AII-CaSO4. A structural model for � -CaSO4 · 0.5H2O is proposed on the basis of SR-PXD data and a trigonal unit cell (in hexagonal setting) a ) 6.931 45(3), c ) 12.736 17(4) A, Z ) 6, and space group P31. A structural model for soluble anhydrite AIII-CaSO4 is also proposed on the basis of powder neutron diffraction data, and a hexagonal unit cell parameters are a ) 6.9687(1), c ) 6.3004(1) A, Z ) 3, and space group P6222.

A small-angle X-ray scattering (SAXS) set-up has recently been developed at beamline I711 at the MAX II storage ring in Lund (Sweden). An overview of the required modifications is presented here together with a number of application examples. The accessible q range in a SAXS experiment is 0.009-0.3 A(-1) for the standard set-up but depends on the sample-to-detector distance, detector offset, beamstop size and wavelength. The SAXS camera has been designed to have a low background and has three collinear slit sets for collimating the incident beam. The standard beam size is about 0.37 mm x 0.37 mm (full width at half-maximum) at the sample position, with a flux of 4 x 10(10) photons s(-1) and lambda = 1.1 A. The vacuum is of the order of 0.05 mbar in the unbroken beam path from the first slits until the exit window in front of the detector. A large sample chamber with a number of lead-throughs allows different sample environments to be mounted. This station is used for measurements on weakly scattering proteins in solutions and also for colloids, polymers and other nanoscale structures. A special application supported by the beamline is the effort to establish a micro-fluidic sample environment for structural analysis of samples that are only available in limited quantities. Overall, this work demonstrates how a cost-effective SAXS station can be constructed on a multipurpose beamline.

Lithium tetrahydridoboranate (LiBH4) may be a potentially interesting material for hydrogen storage, but in order to absorb and desorb hydrogen routinely and reversibly, the kinetics and thermodynamics need to be improved significantly. A priori, this material has one of the highest theoretical gravimetric hydrogen contents, 18.5 wt %, but unfortunately for practical applications, hydrogen release occurs at too high temperature in a non-reversible way. By means of in situ synchrotron radiation powder X-ray diffraction (SR-PXD), the interaction between LiBH4 and different additives-SiO2, TiCl3, LiCl, and Au-is investigated. It is found that silicon dioxide reacts with molten LiBH4 and forms Li2SiO3 or Li4SiO4 at relatively low amounts of SiO2, e.g., with 5.0 and 9.9 mol % SiO2 in LiBH4, whereas, for higher amounts of SiO2 (e.g., 25.5 mol %), only the Li2SiO3 phase is observed. Furthermore, we demonstrate that a solid-state reaction occurs between LiBH4 and TiCl3 to form LiCl at room temperature. At elevated temperatures, more LiCl is formed simultaneously with a decrease in the diffracted intensity from TiCl3. Lithium chloride shows some solubility in solid LiBH 4 at T > 100°C. This is the first report of substituents that accommodate the structure of LiBH4 by a solid/solid dissolution reaction. Gold is found to react with molten LiBH4 forming a Li-Au alloy with CuAu3-type structure. These studies demonstrate that molten LiBH4 has a high reactivity, and finding a catalyst for this H-rich system may be a challenge. © 2008 American Chemical Society.

A new beamline, Cassiopeia, at MAX II is about to come into operation. It consists of an energy‐tunable station and four side stations intended for macromolecular crystallography. The X‐ray source is a 3.5 T superconducting multipole wiggler installed in the 1.5 GeV MAX II storage ring. The energy‐tunable station use grazing incidence Rh‐coated silicon mirrors and an internally water‐cooled Si(111) double‐crystal monochromator while the four side stations use bent diamond and germanium monochromators and multilayer mirrors. This paper concentrates on the optics design of the energy‐tunable station and also briefly describes other beamline components.