TY - JOUR A1 - Katsikini, M. A1 - Filintoglou, K. A1 - Pinakidou, F. A1 - Pilatsikas, N. A1 - Arvanitidis, J. A1 - Christofilos, D. A1 - Paloura, E.C. A1 - Ves, S. A1 - Reinholz, Uwe A1 - Papadomanolaki, E. A1 - Lliopoulos, E. T1 - Scaling of phonon frequencies and electron binding energies with interatomic distances in InxGa1−xN N2 - In-K-edge x-ray absorption fine structure (EXAFS), x-ray photoelectron, and Raman spectroscopy results are combined for a comprehensive study of InxGa1−xN layers with energy gaps extending over nearly the whole visible spectrum. The In–N and In–(In,Ga) distances determind by EXAFS are used for the derivation of the In–N bond ionicity as well as for the phonon frequency dependence of the LO and B21 modes, assessed by Raman, and the N 1s, In 3d5/2, Ga 3s, and Ga 2p1/2 electron binding energies on those distances. Phonon confinement due to perturbation of the periodic potential caused by the alloying is also quantified. KW - Band gap KW - Phonons KW - Epitaxy KW - Electronic structure KW - X-ray photoelectron KW - Nitrides PY - 2021 DO - https://doi.org/10.1063/5.0069359 VL - 130 IS - 20 SP - 205706 - 1 EP - 205706 - 9 PB - AIP Publishing AN - OPUS4-53956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinholz, Uwe A1 - Bremser, Wolfram A1 - Brzezinka, Klaus-Werner A1 - Strub, Erik A1 - Weise, Hans-Peter A1 - Merchel, Silke T1 - A thin-layer reference material for hydrogen analysis N2 - In many areas of material sciences, hydrogen analysis is of particular importance. For example, hydrogen is most abundant as impurity in thin film materials – depending on the deposition process – and has great influence on the chemical, physical and electrical properties of many materials. Existing bulk reference materials (RMs) are not suited for surface sensitive analytical methods like elastic recoil detection analysis (ERDA) or nuclear reaction analysis (NRA). To overcome this serious lack of (certified) thin-layer reference materials for the determination of hydrogen in the near-surface region (1–2 µm depth), we produced stable, homogeneous amorphous silicon layers on Si-wafers (aSi:H–Si) by means of chemical vapour deposition (CVD), while about 10% of hydrogen was incorporated in the Si-layer. Homogeneity and stability were proved by NRA whereas traceability of reference values has been assured by an international interlaboratory comparison. KW - Hydrogen KW - Nuclear reaction analysis KW - Depth profiling KW - Reference material KW - Ion beam analysis PY - 2008 DO - https://doi.org/10.1016/j.nimb.2008.03.015 SN - 0168-583X SN - 1872-9584 VL - 266 IS - 10 SP - 2418 EP - 2423 PB - Elsevier CY - Amsterdam AN - OPUS4-17553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leschik, M. A1 - Heide, G. A1 - Frischat, G.H. A1 - Behrens, H. A1 - Wiedenbeck, M. A1 - Wagner, N. A1 - Heide, K. A1 - Geißler, Heinz A1 - Reinholz, Uwe T1 - Determination of H2O and D2O contents in rhyolitic glasses N2 - Five distinct analytical techniques were compared for the quantification of the H2O (0·1-7·4 wt%) and D2O (up to 5·5 wt% D2O) contents in rhyolitic glasses. The hydrogen concentration in obsidians was measured using nuclear reaction analysis (NRA) and converted into H2O concentration. The bulk water content (H2O+D2O) of synthesised glasses was determined using thermal extraction in conjunction with Karl–Fischer titration (KFT). Unextracted H2O was measured by infrared (IR) spectroscopy after remelting the KFT products at high pressure. These well characterised glasses were subsequently used to calibrate secondary ion mass spectrometry (SIMS), infrared and evolved gas analysis (EGA). The calibrations of SIMS for H2O and D2O show a significant matrix effect at H2O and D2O concentrations larger than ~3 mol/l with the relative sensitivity factor (RSF) decreasing with bulk water content. Molar absorption coefficients for the OH stretching vibration band at 3570 cm-1 and the OD stretching vibration band at 2650 cm-1 in the infrared absorption spectra were reinvestigated. In the range 0·1-6 wt% the H2O content of glasses could be reproduced within analytical error using a constant linear molar absorption coefficient. However, it appears that the absorption coefficients for the 3570 cm-1 band as well as for the 2650 cm-1 band both decrease systematically with concentration of dissolved H2O and D2O (epsi3570=80 (±1) - 1·36(±0·23)CH2Ot and epsi2650=61·2(±1) - 2·52(± 0·30)CD2Ot). EGA allows quantification of the H2O content as well as the study of dehydration kinetics. It is shown that H2O is released under vacuum already at room temperature from glasses containing >7 wt% H2O. PY - 2004 UR - http://www.ingentaconnect.com/content/sgt/pcg/2004/00000045/00000004/art00003 SN - 0031-9090 VL - 45 IS - 4 SP - 238 EP - 251 PB - Thornton CY - Sheffield AN - OPUS4-6279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Britzke, Ralf A1 - Bukalis, Gregor A1 - Reinholz, Uwe A1 - Weise, Hans-Peter A1 - Gadebusch, R.D. T1 - An external PIXE study: Mughal painting pigments KW - PIXE KW - Mughal painting KW - Pigments KW - Archaeometry PY - 2005 SN - 0049-8246 VL - 34 SP - 42 EP - 45 PB - Wiley CY - Chichester AN - OPUS4-6846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peuker, Christel A1 - Reinholz, Uwe A1 - Jäger, Christian A1 - Pauli, Jutta A1 - Geißler, Heinz T1 - Extinction coefficients of the OH bands in the IR spectra of basic and water-enriched silicate and aluminosilicate glasses PY - 2003 SN - 0927-4472 VL - 76 IS - 5 SP - 227 EP - 233 PB - Elsevier CY - Amsterdam AN - OPUS4-2781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Castaing, J. A1 - Calligaro, T. A1 - Salomon, J. A1 - Aucouturier, M. A1 - Reinholz, Uwe A1 - Weise, Hans-Peter T1 - Analyses of hydrogen in quartz and in sapphire using depth profiling by ERDA at atmospheric pressure: Comparison with resonant NRA and SIMS N2 - Hydrogen is present in anhydrous materials as a result of their synthesis and of their environment during conservation. IBA provides techniques to measure H concentration depth profiles allowing to identify various aspects of the materials including the history of objects such as gemstones used in cultural heritage. A newly established ERDA set-up, using an external microbeam of alpha particles, has been developed to study hydrated near-surface layers in quartz and sapphire by non-destructive H depth profiling in different atmospheres. The samples were also analysed using resonant NRA and SIMS. KW - Hydrogen KW - Gemstones KW - ERDA KW - External beam KW - Depth profiling PY - 2006 DO - https://doi.org/10.1016/j.nimb.2006.03.066 SN - 0168-583X SN - 1872-9584 VL - 249 IS - 1-2 SP - 608 EP - 611 PB - Elsevier CY - Amsterdam AN - OPUS4-12844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geißler, Heinz A1 - Reinholz, Uwe A1 - Geotti-Bianchini, F. A1 - Preo, M. T1 - Water content of hydrated soda lime silica surface layers with IR spectroscopy and Nuclear Reaction Analysis (NRA) T2 - 3rd ICG TC 14 forum on "water in glass" CY - Edinburgh, Scotland, UK DA - 2001-07-06 PY - 2001 AN - OPUS4-1065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reiche, I. A1 - Gadebusch, R. A1 - Hahn, Oliver A1 - Reinholz, Uwe A1 - Kanngießer, B. A1 - Malzer, W. T1 - Non-destructive investigations of Mughal Miniatures by a Combined Spectroscopic approach: PIXE, 3D-muXRF and UV-VIS spectroscopy KW - PIXE KW - 3D-micro-XRF KW - UV-VIS spectroscopy KW - Archaeometry KW - Cultural heritage PY - 2004 SN - 84-7820-848-8 SP - 4 pages PB - Fernando El Católico CY - Zaragoza AN - OPUS4-7495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reiche, I. A1 - Gadebusch, R.D. A1 - Hahn, Oliver A1 - Reinholz, Uwe A1 - Kanngießer, B. A1 - Malzer, W. T1 - Non-destructive investigations of indian miniatures by a combined spectroscopic approach: Pixe, 3D-muXRF and UV-vis spectroscopy T2 - 34th International Sympsoium on Archaeometry CY - Zaragoza, Spain DA - 2004-05-03 PY - 2004 SN - 84-7820-848-8 SP - 333 EP - 339 PB - Fernando El Católico CY - Zaragoza AN - OPUS4-12362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Röhrich, J. A1 - Damerow, T. A1 - Hahn, W. A1 - Müller, U. A1 - Reinholz, Uwe A1 - Denker, A. T1 - A tandetron as proton injector for the eye tumor therapy in Berlin N2 - The therapy of eye tumors with fast protons is an excellent tool giving very high local control rates. At the Helmholtz-Zentrum Berlin (HZB) almost 1800 patients were treated since 1998. A 2 MV Tandetron™ was installed as injector for the k = 132 HZB cyclotron. Using the standard 358 duoplasmatron ion source with direct extraction of negative hydrogen ions an extremely stable proton beam can be delivered, both on the short-term and the long-term scale. The hair-needle filaments made from thoriated tungsten wires have safe operation times of more than 1000 h. KW - Biomedical equipment KW - Duoplasmatrons KW - Eye KW - Particle beam extraction KW - Radiation therapy KW - Tumours PY - 2012 DO - https://doi.org/10.1063/1.3662475 SN - 0034-6748 SN - 1089-7623 VL - 83 IS - 02B903 SP - 1 EP - 3 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-25721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Reiche, I. A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Guerra, M.F. T1 - Beyond the Great Wall: Gold of the silk roads and the first empire of the Steppes N2 - Fingerprinting ancient gold work requires the use of nondestructive techniques with high spatial resolution (down to 25 µm) and good detection limits (micrograms per gram level). In this work experimental setups and protocols for synchrotron radiation induced X-ray fluorescence (SRXRF) at the BAMline of the Berlin electron storage ring company for synchrotron radiation (BESSY) in Berlin for the measurement of characteristic trace elements of gold are compared considering the difficulties, shown in previous works, connected to the quantification of Pt. The best experimental conditions and calculation methods were achieved by using an excitation energy of 11.58 keV, a silicon drift chamber detector (SDD) detector, and pure element reference standards. A detection limit of 3 µg/g has been reached. This newly developed method was successfully applied to provenancing the Xiongnu gold from the Gol Mod necropolis, excavated under the aegis of the United Nations Educational, Scientific and Cultural Organization (UNESCO). The composition of the base alloys and the presence of Pt and Sn showed that, contrary to what is expected, the gold foils from the first powerful empire of the steppes along the Great Wall were produced with alluvial gold from local placer deposits located in Zaamar, Boroo, and in the Selenga River. KW - Synchrotron radiation KW - X-ray fluorescence KW - Limit of detection KW - Platinum KW - Silicon drift detector KW - SR-microXRF KW - Elemental imaging KW - Gold PY - 2013 DO - https://doi.org/10.1021/ac3025416 SN - 0003-2700 SN - 1520-6882 VL - 85 IS - 3 SP - 1650 EP - 1656 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guilherme, A. A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Coroado, J. A1 - Dos Santos, J.M.F. A1 - Carvalho, M.L. T1 - Synchrotron micro-XRF with compound refractive lenses (CRLs) for tracing key elements on Portuguese glazed ceramics N2 - Several glazed ceramic fragments (XVIth to XVIIIth centuries) from two production centers in Portugal (Coimbra and Lisbon) were the object of this study. The ones from Coimbra comprise two sets of samples: faiences and tiles. The ones from Lisbon are only tiles (azulejos, in Portuguese). The three main divisions of such pieces are the ceramic support (body), glaze and surface decoration. The system decoration/glaze is not easy to investigate, due to the high heterogeneity resulting from the mixing procedures and firing temperatures used. Moreover, the ability of the pigment to diffuse into the base glaze varies depending on the composition of both the pigment and the glaze in terms of fusibility. In order to raster these effects, high resolution techniques are required. In this work, synchrotron micro-X-ray fluorescence (µ-XRF) analysis was performed to monitor the profiles of the characteristic elements from the colors used and the glaze in well prepared cross-sections of the samples. Key elements are: Co for blue, Mn for purple, Cu for green, Sb for yellow, Pb for the glaze and Fe for the body. The major difference observed is that faiences have glaze thicknesses between 150 and 200 µm and tiles have glaze thicknesses between 350 and 400 µm. Furthermore, in faiences all the pigments except the yellow ones are well dispersed into the glassy matrix, while in tiles, all of them are just partially diffused throughout the glaze. However, differences between the tiles from Coimbra and Lisbon were observed. In the samples from Lisbon, a higher intake from the pigment throughout the glaze is observed. KW - Synchrotron micro-XRF KW - Compound refractive lenses (CRLs) KW - Portuguese glazed ceramics PY - 2012 DO - https://doi.org/10.1039/c2ja30030c SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 6 SP - 966 EP - 974 PB - Royal Society of Chemistry CY - London AN - OPUS4-26789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Streli, C. T1 - Impurities in multicrystalline silicon wafers for solar cells detected by synchrotron micro-beam X-ray fluorescence analysis N2 - We report on the trace analysis of copper and iron impurities in multicrystalline silicon wafers with the microbeam X-ray fluorescence (µ-XRF) technique. The efficiency of solar cells, which are based on multicrystalline silicon wafers, is strongly influenced by minor contamination with metals such as copper and iron. Application of compound refractive lenses (CRLs) in µ-XRF allows versatile two-dimensional mapping of relevant contaminations and localization of their sites of deposition. In this context, the measured bulk average limit of detection (LOD) was one picogram of iron and copper per gram of silicon. We suggest that µ-XRF is a valuable tool for non-destructive spatial (3D) quantification of metal impurities in a wide range of materials and devices whose functioning could be critically affected by impurities. KW - X-ray micro beam KW - Compound refractive lens KW - Solar cell KW - Silicon impurities PY - 2012 DO - https://doi.org/10.1039/c2ja30188a SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 11 SP - 1875 EP - 1881 PB - Royal Society of Chemistry CY - London AN - OPUS4-26791 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Hampel, S. A1 - Fittschen, UEA A1 - Streli, C. A1 - Radtke, Martin T1 - Reconstruction for coded aperture full-field x-ray fluorescence imaging N2 - X-ray fluorescence imaging is a well-established tool in materials characterization. In this work, we present the adaption of coded aperture imaging to full-field X-ray fluorescence imaging at the synchrotron. Coded aperture imaging has its origins in astrophysics, and has several advantages: Coded apertures are relatively easy to fabricate, achromatic, allow a high photon throughput, and high angular acceptance. Coded aperture imaging is a two-step-process, consisting of the measurement process and a reconstruction step. Different programs have been written, for the raytracing/forward projection and the reconstruction. Experiments with coded aperture in combination with a Color X-ray Camera and an energy-dispersive area detector, have been conducted at the BAMline. Measured samples were successfully reconstructed, and gave a 9.1-fold increase in count rate compared to a polycapillary optic. KW - Synchrotron KW - BAMline KW - Coded Aperture PY - 2022 SN - 1097-0002 VL - 65 SP - 57 EP - 70 PB - Cambridge University Press CY - Cambridge AN - OPUS4-56350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brieger, C. A1 - Melke, J. A1 - van der Bosch, N. A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - de Oliveira Guilherme Buzanich, Ana A1 - Krishna Kayarkatte, M. A1 - Derr, I. A1 - Schökel, A. A1 - Roth, C. ED - de Oliveira Guilherme Buzanich, Ana T1 - A combined in-situ XAS–DRIFTS study unraveling adsorbate induced changes on Pt nanoparticle structure N2 - The adsorption behavior of Platinum nanoparticles was studied for the as-received catalyst (under inert gas), under hydrogen and CO atmosphere using our newly designed in-situ cell. X-ray Absorption Spectroscopy (XAS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) experiments were performed simultaneously with high data quality. Structural information and the type of adsorbate could be revealed via Extended X-ray Absorption Fine Structure (EXAFS) analysis, Δμ X-ray Absorption Near Edge Structure analysis (Δμ XANES) and in-situ DRIFTS. The as-received catalyst showed sub-surface oxygen and O(n-fold). Under CO atmosphere only CO(atop) was found. Reversible adsorbate induced changes of the Pt nanoparticle structure were derived from changes in the Pt-Pt coordination number and the corresponding bond distance. Under reducing conditions (H2, CO) a significant increase in both values occurred. Temperature dependent desorption of CO revealed a gradual shift from Pt-CO to Pt-O. Reoxidation was clearly assigned to strong metal support interaction from the SiO2 support. KW - X-ray absorption spectroscopy KW - DRIFTS KW - XANES KW - CO adsoprtion KW - Platinum KW - String metal support interaction KW - Silica support KW - Adsorbates KW - Infrared spectroscopy PY - 2016 DO - https://doi.org/10.1016/j.jcat.2016.03.034 SN - 0021-9517 VL - 339 SP - 57 EP - 67 PB - Elsevier AN - OPUS4-38367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tissot, I. A1 - Troalen, L.G. A1 - Manso, M. A1 - Ponting, M. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Barreiros, M. A. A1 - Shaw, I. A1 - Carvalho, M.L. A1 - Guerra, M.F. T1 - A multi-analytical approach to gold in Ancient Egypt: Studies on provenance and corrosion N2 - Recent results from a three-year multi-disciplinary project on Ancient Egyptian gold jewellery revealed that items of jewellery from the Middle Kingdom to the New Kingdom were manufactured using a variety of alluvial gold alloys. These alloys cover a wide range of colours and the majority contain Platinum Group Elements inclusions. However, in all the gold foils analysed, these inclusions were found to be absent. In this work a selection of gilded wood and leather items and gold foil fragments, all from the excavations by John Garstang at Abydos (primarily from Middle Kingdom graves), were examined using Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS), X-Ray Fluorescence (µXRF), Particle Induced X-Ray Emission (µPIXE) and Double Dispersive X-Ray Fluorescence (D²XRF). The work allowed us to characterise the composition of the base-alloys and also to reveal the presence of Pt at trace levels, confirming the use of alluvial gold deposits. Corrosion products were also investigated in the foils where surface tarnish was visually observed. Results showed that the differences in the colour of corrosion observed for the foils are related not only to the thickness of the corrosion layer but also to a multi-layer structure containing the various corrosion products. KW - Gold KW - Egypt KW - PGE KW - Provenance KW - Corrosion KW - muXRF KW - muPIXE KW - D2XRF KW - SEM-EDS PY - 2015 DO - https://doi.org/10.1016/j.sab.2015.03.012 SN - 0584-8547 SN - 0038-6987 VL - 108 SP - 75 EP - 82 PB - Elsevier CY - Amsterdam AN - OPUS4-33155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mans, C. A1 - Simons, C. A1 - Hanning, S. A1 - Janßen, A. A1 - Alber, D. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Bühler, A. A1 - Kreyenschmidt, M. T1 - New polymeric candidate reference materials for XRF and LA-ICP-MS - development and preliminary characterization N2 - A set of ten calibration materials based on acrylonitrile-butadiene-styrene terpolymer (ABS) containing the elements Br, Pb, Cd, Cr, and Hg was produced in order to control polymer samples in regard to the restriction on the use of certain hazardous substances (RoHS) directive. The materials were produced with respect to the special demands of X-ray fluorescence analysis (XRF) and inductively coupled plasma mass spectrometry in combination with laser ablation (LA-ICP-MS). The mass fractions of all elements were 0-1500 mg/kg and the materials were produced as granulates and solid discs with a diameter of 40 mm and thicknesses of 1, 2, and 6 mm. It could be shown that the signals measured by XRF strongly depend on the thickness of polymeric samples. Macroscopic homogeneity was assessed with XRF measuring a total of 180 samples. The microscopic homogeneities were determined for a material with average elemental mass fractions with the aid of synchrotron radiation (SR) µ-XRF and LA-ICP-MS. Sufficient macroscopic and microscopic homogeneities for all elements could be achieved. It was observed that organic additives show a better homogeneity than oxides. XRF and LA-ICP-MS were successfully calibrated with the new materials. Limits of detection were in the range of 0.4-22 mg/kg for XRF and 2.3-26.8 mg/kg for LA-ICP-MS. The materials are considered as candidate reference materials (RM) by the Federal Institute of Materials Research and Testing (BAM, Germany). KW - XRF KW - LA.ICP-MS Plastics KW - RoHS KW - CRM PY - 2009 DO - https://doi.org/10.1002/xrs.1120 SN - 0049-8246 VL - 38 IS - 1 SP - 52 EP - 57 PB - Wiley CY - Chichester AN - OPUS4-18681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Hampel, S. A1 - Fittschen, U.E.A. A1 - Streli, C. A1 - Radtke, Martin T1 - Comparison of three reconstruction methods based on deconvolution, iterative algorithm and neural network for X-ray fluorescence imaging with coded apertures N2 - X-ray imaging methods are used in many fields of research, as they allow a non-destructive Investigation of the elemental content of various samples. As for every imaging method, for X-ray imaging the optics are of crucial importance. However, these optics can be very expensive and laborious to build, as the requirements on surface roughness and precision are extremely high. Angles of reflection and refraction are often in the range of a few mrad, making a compact design hard to achieve. In this work we present a possibility to simplify X-ray imaging. We have adapted the coded aperture method, a high energy radiation imaging method that has its origins in astrophysics, to full field X-ray fluorescence imaging. In coded aperture imaging, an object is projected through a known mask, the coded aperture, onto an area sensitive detector. The resulting image consists of overlapping projections of the object and a reconstruction step is necessary to obtain the information from the recorded image. We recorded fluorescence images of different samples with an energy-dispersive 2D detector (pnCCD) and investigated different reconstruction methods. With a small coded aperture with 12 holes we could significantly increase the count rate compared to measurements with a straight polycapillary optic. We show that the reconstruction of two different samples is possible with a deconvolution approach, an iterative algorithm and a neural network. These results demonstrate that X-ray fluorescence imaging with coded apertures has the potential to deliver good results without scanning and with an improved count rate, so that measurement times can be shortened compared to established methods. KW - X-ray fluorescence imaging KW - Coded apertures KW - Imaging KW - Elemental mapping KW - Image reconstruction PY - 2020 DO - https://doi.org/10.1039/d0ja00146e VL - 35 IS - 7 SP - 1423 EP - 1434 PB - Royal Society of Chemistry CY - United Kingdom AN - OPUS4-51518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Polte, Jörg A1 - Kraehnert, R. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Emmerling, Franziska T1 - New insights of the nucleation and growth process of gold nanoparticles via in situ coupling of SAXS and XANES N2 - Although metallic nanoparticles play an important role in the area of nanotechnology, a coherent mechanistic explanation for the evolution of the particles during their chemical synthesis has not yet been provided in many cases. To gain a profound understanding of the growth mechanism of colloidal nanoparticles, new approaches using Small Angle X-Ray Scattering (SAXS) combined with X-ray absorption near-edge structure (XANES) are presented. This combination allows for insights into two prominent syntheses routes of gold nanoparticles (GNP): The 'slow' reaction using sodium citrate (30-90 min) as a reducing agent and the 'fast' reaction employing NaBH4 (within few seconds). In the first case data derived with the coupled XANES and SAXS suggests a four-step particle formation mechanism. For the second system a time resolution in the order of 100-200 ms was achieved by coupling a common laboratory SAXS instrument with a microstructured mixer, which allows data acquisition in a continuous-flow mode. The results indicate a coalescence driven growth process. Based on the capabilities to deduce the size, number and polydispersity of the particles, the results of both methods enable the development of mechanistic schemes explaining the different phases of particle formation and growth, thus providing a basis for improved control over the synthesis processes. KW - SAXS KW - XANES KW - Nanoparticle formation PY - 2010 DO - https://doi.org/10.1088/1742-6596/247/1/012051 SN - 1742-6588 SN - 1742-6596 VL - 247 IS - 1 SP - 012051-1 - 012051-10 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-22684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strub, Erik A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Reznikova, E. T1 - Measurements with compound refractive lenses at the "BAMline" N2 - A set of compound refractive lenses (CRLs), mounted on a silicon wafer, was obtained from the Institut für Mikrostrukturtechnik Karlsruhe. The CRLs were characterized at the BAMline at the synchrotron BESSYII in Berlin. It could be demonstrated that beam diameters below 1 µm can be obtained. The beam size accepted by the lenses is (140 × 140) µm2, thus the intensity gain in the micrometer spot, including absorption, is about 15,000. It is possible to switch between different beam energies within a few minutes. First results of scans and the application of the lenses for MicroXANES (X-ray absorption near-edge structure) measurements are presented in this paper. Also, the possibility of MicroEXAFS (extended X-ray absorption fine structure) measurements is discussed. KW - X-ray optics KW - XANES KW - EXAFS KW - XAS KW - XRF KW - Speciation PY - 2008 DO - https://doi.org/10.1016/j.nimb.2008.02.057 SN - 0168-583X SN - 1872-9584 VL - 266 IS - 10 SP - 2165 EP - 2168 PB - Elsevier CY - Amsterdam AN - OPUS4-17554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -