TY - JOUR A1 - Maltsev, Y. A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Rogozev, B. T1 - Precision in Mössbauer Spectroscopy N2 - In this paper the factors which are responsible for precision and reliability of the experimental data are discussed. The detectors of different types are compared with respect to the precision of the final results. It is shown that the use of resonance detectors gives the best results in most cases of the Sn-119m Mössbauer spectroscopy. The estimation of spectral line distortion caused by a short distance between source and detector is presented. Different procedures of velocity scale calibration are discussed. It has to be underlined that Kuprijanov's method of the velocity scale calibration gives the most reliable and fast results. T2 - 5th International Symposium on the Industrial Applications of the Mössbauer Effect (ISIAME) CY - Virginia Beach, VA, USA DA - 2000-08-13 PY - 2002 DO - https://doi.org/10.1023/A:1021203718759 SN - 0304-3843 SN - 1572-9540 VL - 139-140 IS - 1-4 SP - 679 EP - 684 PB - Kluwer CY - Dordrecht AN - OPUS4-2257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, F. A1 - Schmidt, C. A1 - Löffler, E. A1 - Menzel, Michael A1 - Grünert, W. T1 - Fe-ZSM-5 Catalysts for the Selective Reduction of NO by Isobutane - The Problem of the Active Sites N2 - Relations between the structure of Fe–ZSM-5 catalysts prepared by interaction of FeCl3 with H–ZSM-5 and their catalytic behavior in the SCR of NO by isobutane were investigated by combining results of catalytic studies (1000 ppm NO, 1000 ppm isobutane, and 2% O2 in He, 30,000 h-1) and of physicochemical characterization (XRD, EXAFS, Mössbauer spectroscopy, TPR, IR, XPS). By variation of the preparation conditions (method of FeCl3 introduction—chemical vapor deposition or solid-state ion exchange, washing intensity, calcination regime) and of the matrix (H–ZSM-5 with normal and high defect density), Fe–ZSM-5 materials with strongly varying properties (aggregation degree of the Fe phase, acidity) were obtained. Significant discrepancies between conclusions derived from EXAFS, TPR, and Mössbauer spectroscopy were ascribed to a preference of Mössbauer spectroscopy for the detection of aggregated phases and a high defectivity of Fe oxide clusters formed upon calcination. The critical step for the preparation of a highly disperse Fe phase is extensive washing after Fe introduction. The catalytic behavior of overexchanged Fe–ZSM-5 materials prepared by interaction of FeCl3 with H–ZSM-5 of normal defect density was not influenced by aggregation of a significant part of the Fe phase. The comparison of their catalytic properties with those of a Fe2O3/H–ZSM-5 mechanical mixture and of catalysts prepared by aqueous ion exchange or by CVD of FeCl3 into H–ZSM-5 of high defect density implies that the particular activity of overexchanged Fe–ZSM-5 arises from minority sites. In these, the Fe ions are probably isolated. Other Fe sites of low nuclearity appear to add to the activity. The poor SCR performance (at a given ability for isobutane activation) of Fe–ZSM-5 prepared with a defective ZSM-5 matrix may indicate that the Fe sites which provi de the particular activity of overexchanged Fe–ZSM-5 require the cooperation of acidic sites. KW - deNOx KW - Hydrocarbons KW - Isobutane KW - Fe-ZSM-5 KW - EXAFS KW - Mössbauer spectroscopy KW - Temperature-programmed reduction PY - 2002 DO - https://doi.org/10.1006/jcat.2002.3775 SN - 0021-9517 SN - 1090-2694 VL - 212 SP - 157 EP - 172 PB - Acad. Press CY - San Diego, Calif. AN - OPUS4-2258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmauke, T. A1 - Menzel, Michael A1 - Roduner, E. T1 - Magnetic properties and oxidation state of iron in bimetallic Pt-Fe/KL zeolite catalysts N2 - In view of an understanding of catalytic efficiency the electronic and magnetic state of iron in Fe/KL and the influence of Pt on these properties in Pt-Fe/KL were investigated by superconducting quantum interference device (SQUID) magnetization measurements and Mössbauer spectroscopy. After calcination in air, iron is present only as Fe3+ ions in both samples, mainly in a paramagnetic state. There is also a small antiferromagnetic contribution, probably due to iron oxide and hydroxide particles which precipitate on the outer surface of the zeolite crystallites during preparation. After reduction in H2, the behavior of both samples is predominantly superparamagnetic, but the presence of Pt increases both the saturation magnetization and the size of the residual hysteresis loop. At the same there remains a pronounced paramagnetic contribution which appears to be even slightly higher than before reduction. The interpretation is that alloy particles of metallic Pt–Fe are formed on the outer surface. Since small clusters inside the zeolite crystallites are most active for catalysis the alloy formation seems to be not of relevance for an enhancement of sulfur resistance. It was also shown that during reduction a fraction of Fe2+ is formed. The coordination of the Fe2+ ions is clearly influenced by Pt and it seems very likely that Fe2+ ions are in close contact with Pt clusters. This interaction is probably the origin of the enhanced sulfur resistance and catalytic activity in the reforming reactions. KW - Pt-Fe/KL zeolite KW - SQUID magnetization measurements KW - Mössbauer spectroscopy KW - Oxidation state of iron KW - Pt-Fe alloy PY - 2003 DO - https://doi.org/10.1016/S1381-1169(02)00522-8 SN - 1381-1169 SN - 1873-314X VL - 194 SP - 211 EP - 225 PB - Elsevier CY - Amsterdam AN - OPUS4-2296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reuther, H. A1 - Menzel, Michael A1 - Vinnichenko, M. A1 - Kolitsch, A. ED - Garcia, M. T1 - Investigation of the Sn4+ Charge Density Variation in In2O3 using Mössbauer Spectroscopy T2 - International Symposium on the Industrial Application of the Mössbauer Effect CY - Madrid, Spain DA - 2004-10-04 PY - 2005 SN - 0-7354-0250-7 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 765 SP - 132 EP - 136 PB - American Inst. of Physics CY - Melville AN - OPUS4-12150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cieslak, J. A1 - Dubiel, S.M. A1 - Eichhorn, F. A1 - Menzel, Michael A1 - Reuther, H. T1 - Investigation of single-crystals of chromium implanted with 119Sn-ions of various energies N2 - Single-crystals of chromium doped with 10 16 119Sn ions per cm2 and energies ranging between 45 and 190 keV were investigated with conversion electron Mössbauer spectroscopy (CEMS), Auger electron spectroscopy (AES), grazing angle X-ray diffraction (GAXRD), and scanning electron microscopy (SEM). The Mössbauer spectra were found to be significantly different than those of the bulk. Both the maximum and the average hf. field values were higher by a factor of ˜3 than the corresponding quantities for the bulk. The overall shape of the spectra is also different. GAXRD study has revealed that the near-surface zone of the investigated samples has a nanocrystalline structure with the average size of grains ranging between ˜20 and ˜40 nm. The latter seems to be the main reason for the observed enhancement of the spin-density and its distortion. KW - Magnetically ordered materials KW - Crystal growth KW - Hyperfine interactions KW - Mössbauer spectroscopy PY - 2007 DO - https://doi.org/10.1016/j.jallcom.2006.07.143 SN - 0925-8388 SN - 1873-4669 VL - 442 IS - 1-2 SP - 235 EP - 238 PB - Elsevier Sequoia CY - Lausanne AN - OPUS4-15730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael T1 - Influence on the Coordination Sphere of Fe(III) Spin Crossover Compounds T2 - International Conference on the Application of the Mössbauer Effect (ICAME 2013) CY - Opatija, Croatia DA - 2013-09-01 PY - 2013 AN - OPUS4-28989 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Berndt, H. A1 - Mönnich, I. A1 - Lücke, B. T1 - Tin promoted palladium catalysts for nitrate removal from drinking water N2 - Hydrogenation of nitrate to nitrogen using Pd/Al2O3 catalysts promoted by a second metal offers a promising process for nitrate removal in drinking water treatment. This study was aimed to elucidate the nature and function of promoting tin species in PdSn/Al2O3 catalysts obtained in different preparation routes. On one hand, a parent Pd/Al2O3 catalyst was doped via impregnation with aqueous solutions of SnCl2 of different concentrations. On the other hand, the palladium surface of the same parent Pd/Al2O3 catalyst was modified via controlled surface reaction (CSR) with hexane solutions of Sn(C4H9)4. The structure of the different PdSn/Al2O3 catalysts was investigated by 119Sn-Mössbauer spectroscopy and by means of various chemisorption techniques (static and pulse chemisorption of H2 or CO, measurement of the differential heat of CO chemisorption, FTIR spectroscopy of CO chemisorption). Catalytic properties were studied in batch experiments under atmospheric pressure. Promoting of the Pd/Al2O3 catalyst by CSR resulted in catalysts with a significantly higher activity compared to PdSn/Al2O3 catalysts obtained via incipient wetness method. Obviously, Sn(II)-species being present in the latter in high portion inhibit the nitrate reduction on bimetallic PdSn ensembles. CO chemisorption reflected a ‘palladium site blocking’ by tin species in both kinds of catalysts and indirectly indicated the generation of palladium–tin ensembles. In case of the CSR preparation the palladium is alloyed by metallic tin. The palladium surface is diluted by tin atoms, i.e. bimetallic PdSnx ensembles are generated which are able to adsorb and activate nitrate ions. There is an optimum of tin loading, i.e. the activity decreases and the undesired ammonium production in a site reaction increases when the surface becomes too tin rich. Sn(II) species, being preferentially present in catalysts obtained by SnCl2 impregnation also strongly modify the chemisorption properties of the palladium surface, but obviously these species inhibit the nitrate reduction on the bimetallic PdSn ensembles, which are also present in these catalysts. KW - Nitrate hydrogenation KW - Drinking water treatment KW - Bimetallic catalysts KW - Characterization KW - Palladium-tin interactions PY - 2001 DO - https://doi.org/10.1016/S0926-3373(00)00225-3 SN - 0926-3373 SN - 1873-3883 VL - 30 IS - 1-2 SP - 111 EP - 122 PB - Elsevier CY - Amsterdam AN - OPUS4-1021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Uzoukwu, B.A. A1 - Gloe, K. A1 - Rademacher, O. T1 - Synthesis, Spectroscopic, and X-Ray Diffraction Studies of cis-Dichlorobis(4-propanoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato) Tin(IV) N2 - Reaction between an aqueous ethanol solution of tin(II) chloride and that of 4-propanoyl-2,4-dihydro-5-methyl-2-phenyl-3 H-pyrazol-3-one in the presence of O2 gave the compound cis-dichlorobis(4-propanoyl-2,4-dihydro-5-methyl-2-phenyl-3 H-pyrazol-3-onato) tin(IV) [(C26H26N4O4)SnCl2]. The compound has a six-coordinated SnIV centre in a distorted octahedral configuration with two chloro ligands in cis position. The tin atom is also at a pseudo two-fold axis of inversion for both the ligand anions and the two cis-chloro ligands. The orange compound crystallizes in the triclinic space group P 1 with unit cell dimensions, a = 8.741(3) Å, b = 12.325(7) Å, c = 13.922(7) Å; = 71.59(4), = 79.39(3), = 75.18(4); Z = 2 and Dx = 1.575 g cm-3. The important bond distances in the chelate ring are Sn-O [2.041 to 2.103 Å], Sn-Cl [2.347 to 2.351 Å], C-O [1.261 to 1.289 Å] and C-C [1.401 Å] the bond angles are O-Sn-O 82.6 to 87.7° and Cl-Sn-Cl 97.59°. The UV, IR, 1H NMR and 119Sn Mössbauer spectral data of the compound are reported and discussed. KW - Tin (IV) complex KW - 4-Acyl-pyrazolone KW - Spectroscopy KW - Crystal structure PY - 2001 DO - https://doi.org/10.1002/1521-3749(200101)627:1<103::AID-ZAAC103>3.0.CO;2-5 SN - 0044-2313 SN - 1521-3749 SN - 0372-7874 SN - 0863-1786 SN - 0863-1778 IS - 627 SP - 103 EP - 107 PB - Wiley-VCH CY - Weinheim AN - OPUS4-1100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Weber, K. A1 - Regener, D. T1 - Characterization of the microstructure of high-chromium cast irons using Mössbauer spectroscopy N2 - The finish grinding process for cement materials uses ball mills with differently sized grinding balls. Because the grinding takes place through the impact and friction of the balls, balls with a high wear resistance are desirable and the materials of choice are the high-chromium white cast irons. This article examines the behavior of these cast irons when subjected to various heat treatments. The emphasis is on the dependence of the microstructure properties on the chemical composition of the alloys and the heat treatment parameters. The content of retained austenite and that of carbon in the martensite phase were determined by the use of Mössbauer spectroscopy. The results verify that a higher proportion of retained austenite with low carbon content and a martensite with higher hardness produce a material with good fracture toughness and resistance to abrasive wear. KW - High-cromium cast irons KW - White cast irons KW - Grinding process of cement materials KW - Grinding balls KW - As-cast grinding balls PY - 2001 DO - https://doi.org/10.1016/S1044-5803(01)00143-7 SN - 1044-5803 SN - 1873-4189 VL - 46 SP - 399 EP - 406 PB - Elsevier CY - New York, NY AN - OPUS4-1205 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Müller, J.-P. A1 - Gähde, J. A1 - Güttler, B. T1 - Plasma-assisted transformation of iron surfaces into magnetite KW - Iron KW - Magnetite KW - Mössbauer spectroscopy KW - Plasma oxidation PY - 1999 SN - 0257-8972 VL - 116-119 SP - 367 EP - 369 PB - Elsevier Science CY - Lausanne AN - OPUS4-773 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Mehner, Hartmut A1 - Mönnich, I. A1 - Berndt, H. T1 - Investigation of PdSn-catalysts for nitrate removal in drinking water processing N2 - PdSn catalysts prepared by various methods and used for nitrate reduction were investigated by means of in situ 119mSn Mössbauer spectroscopy. Characterization by 119mSn Mössbauer spectroscopy revealed significant differences concerning the modification of the palladium particles supported on alumina. The controlled surface reaction preparation method (CSR) leads to formation of PdSn alloys with different tin contents besides small amounts of Sn(II) species and unalloyed metallic Sn. On the other hand the impregnation method leads to a small amount of PdSn alloys and higher contents of Sn(II) species. Sn(IV) species were found in both kinds of catalysts. The CSR prepared PdSn catalysts showed an improved activity and selectivity compared to the catalysts obtained by the impregnation method. PY - 2000 DO - https://doi.org/10.1023/A:1012688627310 SN - 0304-3843 SN - 1572-9540 VL - 126 IS - 126 SP - 89 EP - 93 PB - Kluwer CY - Dordrecht AN - OPUS4-986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menzel, Michael A1 - Maltsev, Y. T1 - Possibilities to improve the precision in Mössbauer spectroscopy T2 - 10th Mössbauer Colloquium CY - Freiberg, Germany DA - 2000-10-04 KW - Mössbauer Spectroscopy PY - 2000 AN - OPUS4-907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, Michael A1 - Uzoukwu, B. A. A1 - Gloe, K. A1 - Wawrzyniak, K. T1 - Syntheses and 119Sn Mössbauer spectral characterization of tin(IV) complexes of 4-acyl-1-phenyl-3-methylpyrazolones-5 and molecular modelling of 4-acetyl-1-phenyl-3-methylpyrazolone-5 PY - 2004 SN - 0019-5103 VL - 43 SP - 701 EP - 705 PB - Pergamon Press CY - Oxford AN - OPUS4-908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lucka, R. A1 - Elshani, B. A1 - Kilic, M. S. A1 - Klimke, S. A1 - Krüger, C. A1 - Menzel, Michael A1 - Stößer, R. A1 - Titiš, J. A1 - Boča, R. A1 - Renz, F. T1 - ESR and Mössbauer spectroscopy of iron(III) spin crossover complexes based on pentadentate Schiff base ligands with pseudohalide coligands N2 - Two iron(III) spin crossover complexes [Fe(5Cl-L)(NCS)] (1) and [Fe(5Cl-L)(NCSe)] (2) were synthesized with the pentadentate Schiff base ligand 5Cl-L and thiocyanato and selenocyanato as coligands. 5Cl-L, as an asymmetric {N3O2} donor Schiff base, was synthesized by a condensation reaction of 5-chlorosalicyladehyde using the asymmetric N-(2-aminoethyl)-1,3-propanediamine. The complexes exhibited a spin crossover at 280 (1) and 293 K (2), respectively, and were subjected to electron spin resonance (ESR) and Mössbauer spectroscopy at 77, 295 and 325 K. Ab initio CASSCF calculations followed by the NEVPT2 method were applied for predicting the g-tensor components as well as Mössbauer parameters. KW - Spin crossover KW - Iron(III) complexes KW - Mössbauer spectroscopy KW - ESR spectroscopy KW - Ab initio calculations PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634061 DO - https://doi.org/10.3390/magnetochemistry11050043 SN - 2312-7481 VL - 11 IS - 5 SP - 1 EP - 9 PB - MDPI CY - Basel AN - OPUS4-63406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Renz, F. A1 - Jung, S. A1 - Klein, M. A1 - Menzel, Michael A1 - Thünemann, Andreas T1 - Molecular switching complexes with iron and tin as central atom N2 - The precursor [FeIII(L)Cl] (LH