TY - JOUR A1 - Balle, P. A1 - Geiger, B. A1 - Klukowski, D. A1 - Pignatelli, M. A1 - Wohnrau, S. A1 - Menzel, Michael A1 - Zirkwa, I. A1 - Brunklaus, G. A1 - Kureti, S. T1 - Study of the selective catalytic reduction of NOx on an efficient Fe/HBEA zeolite catalyst for heavy duty diesel engines KW - SCR KW - BEA KW - Zeolite KW - Fe KW - Active sites KW - Diesel engine KW - Hydrothermal aging KW - SO2 stability PY - 2009 DO - https://doi.org/10.1016/j.apcatb.2009.06.031 SN - 0926-3373 SN - 1873-3883 VL - 91 IS - 3-4 SP - 587 EP - 595 PB - Elsevier CY - Amsterdam AN - OPUS4-19798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Mössbauer investigations of {Fe/alumogel} systems with Fe(0)-species involved in solid state reactions T2 - 50 Years after - The Mössbauer effect today and in the future, Technische Universität CY - Munich, Germany DA - 2008-10-09 PY - 2008 AN - OPUS4-17965 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Feist, M. A1 - Menzel, Michael A1 - Nofz, Marianne T1 - Fe3+ ions acting as probes and agents in aggregation processes and solid-state reactions in AlO(OH)/Al2O3 matrices N2 - The fate of doped iron species during various mechanically and thermally initiated redox reactions and aggregation processes in crystalline and amorphous AlO(OH) or Al2O3 matrices was investigated. The amorphization of the matrix was performed by chemical (i.e., via sol-gel processes) or mechanochemical treatment (high-energy ball milling). Thermal analysis, coupled with mass spectrometry (TA-MS), Mössbauer spectroscopy, and electron spin resonance (ESR), was used. The TA under various gas atmospheres allowed preparing samples under a controlled temperature regime, together with a controlled gas influence. Both the effect of mechanical activation and the influence of the iron doping could be followed macroscopically via the down-shift of the peak temperature of the corundum formation. The ESR data characterize the Fe3+ ions and their interaction with the magnetic surrounding based on the fine structure parameters. The Mössbauer data allowed the characterization of the Fe(0), Fe2+, and Fe3+ species, together with providing information about their coordinative surrounding. Both methods provided general complementary spectroscopical information. Unexpectedly, (FeOx)n and (FexAl1-x)2O3 aggregates could also be detected in the range of low Fe concentrations. It was demonstrated that even in the low-level doped systems [(FexAl1-x)2O3 with x ≥ 0.01], all the essential spectroscopic phenomena occur. At higher Fe concentrations, they were discovered to be caused by magnetic and spin exchange interactions as well as by solid-state reactions during and after the mechanical activation. PY - 2010 DO - https://doi.org/10.1111/j.1551-2916.2009.03596.x SN - 0002-7820 SN - 1551-2916 VL - 93 IS - 5 SP - 1447 EP - 1456 PB - Blackwell Publishing CY - Malden AN - OPUS4-21235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jung, S. A1 - Renz, F. A1 - Klein, M. A1 - Menzel, Michael A1 - Boca, R. A1 - Stößer, R. T1 - Molecular switching in iron complexes bridged via tincyanides observed by Mössbauer and ESR spectroscopy N2 - The precursor [FeIII(L)Cl] (LH2 = N,N'-bis(2'-hydroxy-3'-X-benzyliden)-1,6-diamino-3-N-hexane) is a high-spin (S = 5/2) complex (with X = -CH3, -O-CH3). This precursor is combined with the bridging unit [SnIV(CN)4] to yield star-shaped pentanuclear clusters, [(L-X-FeIII)4Sn(CN)4]Cl4 57Fe-Mössbauer, 119mSn-Mössbauer, and ESR spectroscopy are used to study our samples. For X = -CH3 the 57Fe-Mössbauer data show a multiple spin transition between iron(III) in the high-spin and low-spin state. Changing the functional group from X = -CH3 to X = -O-CH3 turns the switchability off. KW - Switching iron complexes KW - Spin-transition KW - Mössbauer spectroscopy KW - ESR-spectroscopy PY - 2010 DO - https://doi.org/10.1088/1742-6596/217/1/012027 SN - 1742-6588 SN - 1742-6596 VL - 217 IS - 1 / 012027 SP - 1 EP - 6 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-22561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Menzel, Michael A1 - Feist, M. T1 - The fate of Fe3+ ions in the system {AlO(OH)-xerogel/Fe-compounds} after mechanical activation and different thermal treatments studied by Mössbauer, ESR spectroscopy and thermal analysis KW - Mössbauer KW - ESR KW - Thermal analysis KW - High energy ball milling KW - Activation/deactivation processes KW - Local mechano-chemical reactions KW - Heterogeneous redox reactions PY - 2009 DO - https://doi.org/10.1007/s10751-009-9920-0 SN - 0304-3843 SN - 1572-9540 VL - 190 IS - 1-3 SP - 43 EP - 49 PB - Kluwer CY - Dordrecht AN - OPUS4-19478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stößer, R. A1 - Menzel, Michael A1 - Feist, M. A1 - Nofz, Marianne A1 - Renz, F. T1 - Competing redox reactions in Fe-containing AlO(OH) and Al2O3 matrices: A combined investigation by Mössbauer, ESR spectroscopy and thermal analysis N2 - The investigation of iron-doped AlO(OH)/Al2O3 systems revealed that the combined employment of Mössbauer and ESR spectroscopies together with thermal analysis yields meaningful data with complementary information. This mutual complementarity is based on the coexistence of Fe point defects with the corresponding aggregated FeOx species which has been observed even for very low Fe concentrations. Competing redox processes between the dopant, the AlOx matrix, and the gas atmosphere during the thermal treatment enable the generation of solid phases exhibiting specific chemical properties. The entire reaction process is influenced by a specific mechanical and thermal pre-treatment that affects predominantly oxydative processes in the matrix. A protecting influence of the matrix preventing further reductive attack of the Fe3+ Fe2+ ions by hydrogen has been established. KW - Mössbauer KW - ESR spectroscopy KW - Thermal analysis KW - Al2O3 KW - Magnetite KW - Fe(0) KW - Fe(2+) KW - Fe(3+) PY - 2010 UR - http://iopscience.iop.org/1742-6596/217/1/012028/pdf/1742-6596_217_1_012028.pdf DO - https://doi.org/10.1088/1742-6596/217/1/012028 SN - 1742-6588 SN - 1742-6596 VL - 217 IS - 1 SP - 012028-1 - 012028-5 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-21876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maltsev, Yuri A1 - Maltsev, S. A1 - Menzel, Michael A1 - Rogozev, B. A1 - Silvestrov, A. T1 - Two-Dimensional Mössbauer Spectra N2 - To decrease the spectra measurement time in Mössbauer spectroscopy a new data acquisition system was proposed, which allows to collect data as a two-dimensional distribution. KW - Data acquisition KW - Signal processor KW - Two-dimensional Mössbauer spectrum PY - 2004 DO - https://doi.org/10.1023/B:HYPE.0000043204.05421.b5 SN - 0304-3843 SN - 1572-9540 VL - 156/157 SP - 27 EP - 30 PB - Kluwer CY - Dordrecht AN - OPUS4-4578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Nofz, Marianne T1 - Laboratory Intercomparison on the Determination of the Fe(II)/Fe(III) Ratio in Glass Using Mössbauer Spectroscopy N2 - The Mössbauer community all over the world was given the opportunity to determine the Fe(II)/Fe(III) ratio in 4 glass samples of different total iron content, to classify themselves with respect to their measurement technique and especially to their kind of evaluation. KW - Mössbauer spectroscopy KW - Iron KW - Glass KW - Intercomparison KW - Fe(II)/Fe(III) ratio PY - 2004 DO - https://doi.org/10.1023/B:HYPE.0000043252.55048.63 SN - 0304-3843 SN - 1572-9540 VL - 156-157 SP - 347 EP - 352 PB - Kluwer CY - Dordrecht AN - OPUS4-4579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lawaczeck, R. A1 - Menzel, Michael A1 - Pietsch, H. T1 - Superparamagnetic iron oxide particles: contrast media for magnetic resonance imaging N2 - The mainstream magnetic iron oxide particles used as contrast media for magnetic resonance (MR) imaging are composed of a magnetic iron oxide core surrounded by a dextran or carboxydextran coat. The core size ranges from 2 nm to less than 10 nm, and the hydrodynamic diameter ranges from 20 nm to about 120 nm. The coat prevents aggregation and sedimentation of the particles in aqueous solutions, achieves high biological tolerance, and prevents toxic side effects. Two kinds of particles are considered: (i) large particles (>30 nm), called superparamagnetic iron oxide particles (SPIOs) for liver imaging; (ii) smaller particles (<30 nm hydrodynamic diameter), called ultrasmall SPIOs (USPIOs), e.g. for MR angiography. To characterize the particles, Mössbauer spectra are presented for the two particle ensembles. These spectra allow insight into the magnetic coupling, the valency of the iron ions and a rough estimate of the core size to be deduced. On the basis of the concentration dependence of the MR signal intensities, two applications are discussed together with two representative clinical examples. KW - Superparamagnetic KW - Iron oxide particles KW - MR imaging KW - Contrast media PY - 2004 DO - https://doi.org/10.1002/aoc.753 SN - 0268-2605 SN - 1099-0739 VL - 18 SP - 506 EP - 513 PB - Longman CY - Harlow AN - OPUS4-4580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Erste Erfahrungen mit dem RICON Konversionselektronendetektor T2 - VIIIth Mössbauer Colloquium Freiberg ´96 CY - Freiberg, Germany DA - 1996-09-30 PY - 1996 AN - OPUS4-6223 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Identifizierung verschiedener Zinnphasen in PdSn-Katalysatoren T2 - IXth Mössbauer Colloquium Freiberg ´98 CY - Freiberg, Germany DA - 1998-09-28 PY - 1998 AN - OPUS4-6227 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Characterization of PdSn-catalysts for nitrate removal in drinking water processing T2 - ICAME `99 Conference CY - Garmisch-Partenkirchen, Germany DA - 1999-08-29 PY - 1999 AN - OPUS4-6229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Investigation of iron species in zeolite catalysts by Mössbauer spectroscopy T2 - 5th Seeheim Workshop on Mössbauer Spectroscopy CY - Seeheim-Jugenheim, Germany DA - 2002-05-21 PY - 2002 AN - OPUS4-6234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maltsev, Yuri A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Maslova, Natalija A1 - Rogozev, B. A1 - Kruglov, E. ED - Thomas, M. ED - Williams, J. ED - Gibb, T. T1 - Baseline investigation in transmission Mössbauer spectroscopy using resonance detectors T2 - 26th International Conference on the Applications of the Mössbauer Effect (ICAME 2001) CY - Oxford, England, UK DA - 2001-09-02 KW - Mössbauer spectroscopy KW - Resonance detector KW - Rayleigh scattering of Mössbauer radiation PY - 2003 SN - 1-402-01087-7 SN - 0304-3843 VL - 5 SP - 9 EP - 12 PB - Kluwer Acad. Publ. CY - Dordrecht AN - OPUS4-6930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -