TY - JOUR A1 - Hennig, C. A1 - Takao, S. A1 - Takao, K. A1 - Weiss, s. A1 - Kraus, Werner A1 - Emmerling, Franziska A1 - Meyer, M. A1 - Scheinost, A.C. T1 - Identification of hexanuclear actinide(IV) carboxylates with thorium, uranium and neptunium by EXAFS spectroscopy N2 - Hydrated actinide(IV) ions undergo hydrolysis and further polymerization and precipitation with increasing pH. The resulting amorphous and partly crystalline oxydydroxides AnOn(OH)4-2n·xH2O can usually be observed as colloids above the An(IV) solubility limit. The aging process of such colloids results in crystalline AnO2. The presence of carboxylates in the solution prevents the occurrence of such colloids by formation of polynuclear complexes through a competing reaction between hydrolysis and ligation. The majority of recently described carboxylates reveals a hexanuclear core of [An6(µ3-O)4(µ3-OH)4]12+ terminated by 12 carboxylate ligands. We found that the An(IV) carboxylate solution species remain often preserved in crystalline state. The An(IV) carboxylates show An–An distances which are ~ 0.03 Å shorter than the An–An distances in AnO2 like colloids. The difference in the distances could be used to identify such species in solution. T2 - XAFS15 - 15th International conference on X-ray absorption fine structure CY - Beijing, China DA - 22.07.2012 KW - Carboxylates KW - EXAFS KW - Actinide PY - 2013 DO - https://doi.org/10.1088/1742-6596/430/1/012116 SN - 1742-6588 SN - 1742-6596 VL - 430 SP - 012116-1 EP - 012116-5 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-28525 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Urban, Ingrid A1 - Severin, D. A1 - Trepte, S. T1 - Analyse von Reibschichten auf Bremsbelägen N2 - Die volle Leistung einer auf Reibung basierenden Bremse wird erst nach einem Einlaufvorgang erreicht. Dieser ist notwendig, um auf Belag und Scheibe eine sogenannte Reibschicht aufzubauen. Da diese Zwischenschicht das Reibungsverhalten des Systems maßgeblich bestimmt, ist es wichtig, sich Klarheit über ihre chemische Zusammensetzung, Mikrostruktur und die daraus resultierenden Eigenschaften zu verschaffen. Als Basismaterial diente ein phenolharzgebundener Belag Jurid 57-62, der mit verschiedenen Parametern (Flächenpressung und Umdrehungsgeschwindigkeit) gegen eine Stahlscheibe getestet wurde. Es wurden Dauerbremsungen von jeweils einer Stunde bzw. bis zu einem maximalen Belagverschleiß von 1 mm simuliert, wobei die Entwicklung der Reibzahl und die Oberflächentemperatur der Scheibe registriert wurde. Zur Analyse der Reibschichten auf dem Bremsbelag wurden mehrere Methoden parallel angewandt. So wurden Verschleißpartikel, die aus der Reibschicht stammen, gesammelt bzw. abgekratzt und nach Dispergieren auf Kohlefolien direkt im Transmissionselektronenmikros-kop (TEM) untersucht. Ferner wurden von einigen ausgesuchten Belagproben Mikrotom-schnitte sowie dünne Querschnittsfolien für die TEM-Untersuchung präpariert, um den Verbund Reibschicht-Grundmaterial darstellen zu können. Als Ergänzung wurden ferner oberflächenmorphologische und –analytische Verfahren wie REM/EDX und ESCA eingesetzt. Die Ergebnisse deuten darauf hin, dass die Reibschicht nanokristallin ist, und dass fast alle anorganischen Bestandteile des Bremsbelags sowie Eisenoxid von der Bremsscheibe in sehr fein verteilter Form vorliegen. Bei Belägen ohne Metallanteil bildet eine Barium-Eisen-Sulfatphase offenbar die Grundstruktur der Reibschicht, während auf eisenhaltigen Belägen Eisenoxid dominierend ist. Die nanokristalline Mikrostruktur entsteht, ähnlich wie beim mechanischen Legieren, durch einen Mahlvorgang von Verschleißpartikeln zwischen den Reibpartnern. Bei Überlastung des Belags tritt Zersetzung der Polymer-Bindephase ein, was zu einem raschen Anstieg der Verschleißrate führt. KW - Bremsbelag KW - Reibschicht KW - Reibungskoeffizient KW - Oberflächenanalyse KW - Transmissionselektronenmikroskopie PY - 2000 SN - 0933-5137 VL - 31 SP - 708 EP - 711 PB - Whiley VCH CY - Weinheim AN - OPUS4-38542 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schaepe, Kaija A1 - R. Bhandari, D. A1 - Werner, J. A1 - Henss, A. A1 - Pirkl, A. A1 - Kleine-Boymann, M. A1 - Rohnke, M. A1 - Wenisch, S. A1 - Neumann, E. A1 - Janek, J. A1 - Spengler, B. T1 - Imaging of lipids in native human bone sections using TOF-secondary ion mass spectrometry, atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization orbitrap mass spectrometry, and orbitrap-secondary ion mass spectrometry N2 - A method is described for high-resolution label-free molecular imaging of human bone tissue. To preserve the lipid content and the heterogeneous structure of osseous tissue, 4 μm thick human bone sections were prepared via cryoembedding and tape-assisted cryosectioning, circumventing the application of organic solvents and a decalcification step. A protocol for comparative mass spectrometry imaging (MSI) on the same section was established for initial analysis with time-of-flight secondary ion mass spectrometry (TOF-SIMS) at a lateral resolution of 10 μm to <500 nm, followed by atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) Orbitrap MSI at a lateral resolution of 10 μm. This procedure ultimately enabled MSI of lipids, providing the lateral localization of major lipid classes such as glycero-, glycerophospho-, and sphingolipids. Additionally, the applicability of the recently emerged Orbitrap-TOF-SIMS hybrid system was exemplarily examined and compared to the before-mentioned MSI methods. KW - ToF-SIMS KW - MALDI KW - Mass spectrometry imaging KW - Lipids KW - Osteoporosis KW - Bone KW - Surface analysis PY - 2018 UR - https://pubs.acs.org/doi/10.1021/acs.analchem.8b00892 DO - https://doi.org/10.1021/acs.analchem.8b00892 SN - 0003-2700 SN - 1520-6882 VL - 90 IS - 15 SP - 8856 EP - 8864 PB - ACS Publ. CY - Washington, DC AN - OPUS4-45730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Takao, S. A1 - Takao, K. A1 - Kraus, Werner A1 - Emmerling, Franziska A1 - Scheinost, A.C. A1 - Bernhard, G. A1 - Hennig, C. T1 - First hexanuclear U IV and Th IV formate complexes - Structure and stability range in aqueous solution N2 - The actinide(IV) hexanuclear [M6(μ3-O)4(μ3-OH)4(HCOO)12(LT)6] complexes were prepared (LT = H2O or CH3OH). Their structures were investigated by single-crystal X-ray analysis and XAFS spectroscopy. HCOO– acts as a bridging ligand, which prevents the formation of polynuclear hydrolysis species like UIV hydrous oxide colloids at least up to pH = 3.25, and stabilizes the nanosized clusters in solution. The charge of the hexamer is balanced by the O/OH ratio of the μ3-bridges.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) KW - Actinides KW - Polynuclear species KW - Formic acid KW - Bridging ligands PY - 2009 DO - https://doi.org/10.1002/ejic.200900899 SN - 1434-1948 SN - 1099-0682 VL - 2009 IS - 32 SP - 4771 EP - 4775 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-20329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yusenko, Kirill A1 - Sukhikh, A. A1 - Kraus, Werner A1 - Gromilov, S. T1 - Synthesis and Crystal Chemistry of Octahedral Rhodium(III) Chloroamines N2 - Rhodium(III) octahedral complexes with amine and chloride ligands are the most common starting compounds for preparing catalytically active rhodium(I) and rhodium(III) species. Despite intensive study during the last 100 years, synthesis and crystal structures of rhodium(III) complexes were described only briefly. Some [RhClx(NH3)6-x] compounds are still unknown. In this study, available information about synthetic protocols and the crystal structures of possible [RhClx(NH3)6−x] octahedral species are summarized and critically analyzed. Unknown crystal structuresof(NH4)2[Rh(NH3)Cl5],trans–[Rh(NH3)4Cl2]Cl·H2O,andcis–[Rh(NH3)4Cl2]Clarereported based on high quality single crystal X-ray diffraction data. The crystal structure of [Rh(NH3)5Cl]Cl2 was redetermined. All available crystal structures with octahedral complexes [RhClx(NH3)6-x] were analyzed in terms of their packings and pseudo-translational sublattices. Pseudo-translation lattices suggest face-centered cubic and hexagonal closed-packed sub-cells, where Rh atoms occupy nearly ideal lattices. KW - Pseudo-translationalsublattices KW - Rhodiumcomplexes KW - Ligandsubstitution KW - Crystalstructure PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508194 DO - https://doi.org/10.3390/molecules25040768 VL - 25 IS - 4 SP - 768 PB - MDPI CY - Basel AN - OPUS4-50819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago A1 - Teske, Tanita A1 - Hilgenberg, Kai A1 - Mauro, Madia A1 - Nielsen, S. A1 - Gärtner, F. A1 - Klassen, T. T1 - Untersuchung des Potenzials von Kaltgasspritzen für die Reparatur zyklisch belasteter Bauteile T1 - Investigation on the capability of cold-spray for repair of cyclically loaded components N2 - Die Reparatur mittels Kaltgasspritzen ist eine vielversprechende Alternative zum teuren Austausch fehlerbehafteter Bauteile in der Luft- und Raumfahrt. Im Rahmen dieser Arbeit wurde das Potential des Verfahrens an der hochfesten Aluminiumlegierungen Al6061-T6 unter Anwendung von Stickstoff als kostengünstiges Prozessgas untersucht. Es wurden quasi-statische Zugversuche und einachsige Zeitfestigkeitsversuche mit besonderem Fokus auf das in-situ Kugelstrahlen zur Verbesserung der mechanischen Eigenschaften durchgeführt. Im Ergebnis wurde die Verbesserung der Adhäsion zwischen Substrat und aufgebautem Werkstoff als entscheidendes Kriterium für eine Anwendbarkeit ermittelt. Die Laserstrukturierung von Substratoberflächen ist hierfür vielversprechend und wurde im Rahmen der Arbeit mittels Adhäsionsversuchen untersucht. N2 - Repair by cold-spray is a promising alternative to the costly replacement of flawed components in aerospace applications. In the present work this process was investigated on the high-strength aluminum alloy Al6061-T6. For the cold-spray process, inexpensive Nitrogen was used as process-gas. Quasi-static tensile and highcycle- fatigue tests (HCF) were performed, focusing on in-situ shot peening to improve the mechanical properties of the repaired part. An improved adhesion between substrate and built-up material was identified as a key-factor for the applicability of the process. Under this respect laser-structuring of the substrate surface was applied and its effect on the mechanical performance of the restored samples were examined by adhesion tests. T2 - 9. Tagung des DVM-Arbeitskreises Additiv gefertigte Bauteile und Strukturen CY - Stuttgart, Germany DA - 06.11.2024 KW - Kaltgasspritzen KW - cold-spray KW - Reparatur KW - Repair KW - Ermüdungsfestigkeit KW - Fatigue KW - Luft- und Raumfahrt KW - Aerospace KW - Substratvorbehandlung KW - Substrate pre-treatment PY - 2024 DO - https://doi.org/10.48447/ADD-2024-BB VL - 409 SP - 67 EP - 79 AN - OPUS4-63182 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stephan, H. A1 - Walther, M. A1 - Fähnemann, S. A1 - Ceroni, P. A1 - Molloy, J.K. A1 - Bergamini, G. A1 - Heisig, F. A1 - Müller, C.E. A1 - Kraus, Werner A1 - Comba, P. T1 - Bispidines for dual imaging N2 - The efficient transformation of the hexadentate bispidinol 1 into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY-substituted bispidine 3 combines a coordination site for metal ions, such as radioactive 64CuII, with a fluorescent unit. Product 3 was thoroughly characterized by standard analytical methods, single crystal X-ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand 3 was found to be strongly dependent on metal ion coordination: CuII quenches the BODIPY fluorescence, whereas NiII and ZnII ions do not affect it. It follows that, in imaging applications with the positron emitter 64CuII, residues of its origin from enriched 64Ni and the decay products 64NiII and 64ZnII, efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the 64CuII–3 complex is investigated by transmetalation experiments with ZnII and NiII, using fluorescence and radioactivity detection, and the results confirm the high stability of 64CuII–3. In addition, metal complexes of ligand 3 with the lanthanide ions TbIII, EuIII, and NdIII are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection. KW - Bispidines KW - Chelates KW - Imaging agents KW - Lanthanides KW - Radiolabeling KW - Nuclear medical application KW - Radioactive labelling KW - SPECT PY - 2014 DO - https://doi.org/10.1002/chem.201404086 SN - 0947-6539 SN - 1521-3765 VL - 20 IS - 51 SP - 17011 EP - 17018 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-32320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hennig, C. A1 - Ikeda-Ohno, A. A1 - Kraus, Werner A1 - Weiss, S. A1 - Pattison, P. A1 - Emerich, H. A1 - Abdala, P. M. A1 - Scheinost, A.C. T1 - Crystal structure and solution species of Ce(III) and Ce(IV) formates: From mononuclear to hexanuclear complexes N2 - Cerium(III) and cerium(IV) both form formate complexes. However, their species in aqueous solution and the solid-state structures are surprisingly different. The species in aqueous solutions were investigated with Ce K-edge EXAFS spectroscopy. Ce(III) formate shows only mononuclear complexes, which is in agreement with the predicted mononuclear species of Ce(HCOO)2+ and Ce(HCOO)2+. In contrast, Ce(IV) formate forms in aqueous solution a stable hexanuclear complex of [Ce6(µ3-O)4(µ3-OH)4(HCOO)x(NO3)y]12–x-y. The structural differences reflect the different influence of hydrolysis, which is weak for Ce(III) and strong for Ce(IV). Hydrolysis of Ce(IV) ions causes initial polymerization while complexation through HCOO– results in 12 chelate rings stabilizing the hexanuclear Ce(IV) complex. Crystals were grown from the above-mentioned solutions. Two crystal structures of Ce(IV) formate were determined. Both form a hexanuclear complex with a [Ce6(µ3-O)4(µ3-OH)4]12+ core in aqueous HNO3/HCOOH solution. The pH titration with NaOH resulted in a structure with the composition [Ce6(µ3-O)4(µ3-OH)4(HCOO)10(NO3)2(H2O)3]·(H2O)9.5, while the pH adjustment with NH3 resulted in [Ce6(µ3-O)4(µ3-OH)4(HCOO)10(NO3)4]·(NO3)3(NH4)5(H2O)5. Furthermore, the crystal structure of Ce(III) formate, Ce(HCOO)3, was determined. The coordination polyhedron is a tricapped trigonal prism which is formed exclusively by nine HCOO– ligands. The hexanuclear Ce(IV) formate species from aqueous solution is widely preserved in the crystal structure, whereas the mononuclear solution species of Ce(III) formate undergoes a polymerization during the crystallization process. KW - Crystal structure KW - Ce complexes KW - EXAFS KW - XANES PY - 2013 DO - https://doi.org/10.1021/ic400999j SN - 0020-1669 SN - 1520-510X VL - 52 IS - 20 SP - 11734 EP - 11743 PB - American Chemical Society CY - Washington, DC AN - OPUS4-29850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Griebenow, Werner A1 - Werthmann, Barbara A1 - Treu, Dieter A1 - Hörn, K. A1 - Krause, S. T1 - Zur Identifizierung von Tinten auf alten Handschriften PY - 1983 SN - 0025-1445 SN - 0342-3719 VL - 89 IS - 3 SP - 208 EP - 212 PB - Callwey CY - München AN - OPUS4-38963 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hennig, C. A1 - Weiss, S. A1 - Kraus, Werner A1 - Kretzschmar, J. A1 - Scheinost, A.C. T1 - Solution species and crystal structure of Zr(IV) acetate N2 - Complex formation and the coordination of zirconium with acetic acid were investigated with Zr K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) and single-crystal diffraction. Zr K-edge EXAFS spectra show that a stepwise increase of acetic acid in aqueous solution with 0.1 M Zr(IV) leads to a structural rearrangement from initial tetranuclear hydrolysis species [Zr4(OH)8(OH2)16]8+ to a hexanuclear acetate species Zr6(O)4(OH)4(CH3COO)12. The solution species Zr6(O)4(OH)4(CH3COO)12 was preserved in crystals by slow evaporation of the aqueous solution. Single-crystal diffraction reveals an uncharged hexanuclear cluster in solid Zr6(μ3-O)4(μ3-OH)4(CH3COO)12·8.5H2O. EXAFS measurements show that the structures of the hexanuclear zirconium acetate cluster in solution and the solid state are identical. KW - Complex formation KW - Crystal structure KW - Zr(iV) compounds PY - 2017 DO - https://doi.org/10.1021/acs.inorgchem.6b01624 SN - 0020-1669 SN - 1520-510X VL - 56 IS - 5 SP - 2473 EP - 2480 PB - ACS AN - OPUS4-39677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Krause, S. A1 - Moelders, Theodor A1 - Neidel, A. A1 - Oder, Gabriele A1 - Völker, J. T1 - Influence of heat treatment on microstructure and hot crack susceptibility of laser-drilled turbine blades made from René 80 N2 - Turbine components from conventionally cast nickel-base alloy René 80 show different hot cracking susceptibilities depending on their heat treatment conditions leading to slightly different microstructures. Electron probe micro-analysis, focused ion beam technique and analytical transmission electron microscopy were applied to reveal and identify grain boundary precipitates and the γ–γ'-microstructure. The distribution of borides along grain boundaries was evaluated statistically by quantitative metallography. The following features could be correlated with an increase of cracking susceptibility: i) Increasing grain size, ii) increasing fraction of grain boundaries with densely spaced borides, iii) lack of secondary γ'-particles in matrix channels between the coarse cuboidal γ'-precipitates. The latter feature seems to be responsible for linking-up of cracked grain boundary precipitates which occurred as an additional cracking mechanism after one heat treatment, whereas decohesion at the boride-matrix-interface in the heat affected zone of laser-drilled holes was observed for both heat treatments. KW - Turbine blades KW - Nickel-base superalloy KW - Laser drilling KW - Hotcrack susceptibility KW - Grain boundary precipitates PY - 2008 DO - https://doi.org/10.1016/j.matchar.2008.01.021 SN - 1044-5803 SN - 1873-4189 VL - 59 IS - 11 SP - 1564 EP - 1571 PB - Elsevier CY - New York, NY AN - OPUS4-17932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -