TY - JOUR A1 - Mehner, Hartmut A1 - Feist, M. A1 - Stößer, R. A1 - Scholz, G. A1 - Kemnitz, E. A1 - Dwelk, H. T1 - Halogeno metallates of transition elements with cations of nitrogen-containing heterocyclic bases, IX. Moessbauer and ESR spectroscopic investigation of aquachloro- and bromoferrates(III). On the compatibility of structural information obtained by spectroscopic and diffraction methods JF - Solid state sciences N2 - The 57Fe-Moessbauer spectrum of (dmpipzH2)2[FeIII(H2O)2Cl4][FeIII Cl4]Cl2 (1) consists of two doublets caused by a strongly distorted octahedral and a non-distorted tetrahedral component. Both (dmpipzH2)[FeIIIBr4]2 (2) and (trienH2)[FeIIIBr4]Br (3) show only one doublet indicating a more strongly distorted iron(III) species for 2 and a less-distorted one in the case of 3. For all compounds investigated, the ESR spectra reveal the existence of ground states with predominant antiferromagnetic coupling. The Néel temperatures amount to <4.2 K for 1, 4 K for 3 and 48 K for 2. In the case of 2, both the Moessbauer and the ESR spectra reveal the formation of exchange-coupled {FeBr4} units which has been attributed to a significant cation influence. The fine structure of residual paramagnetic [FeBr4]- subunits remaining in the crystalline matrix could be directly determined. Temperature dependent AC and DC susceptibility measurements of 2 and 3 confirmed the results. KW - Iron coordination KW - Antiferromagnetic coupling KW - Exchange-coupled units KW - ESR fine structure KW - Magnetic susceptibility PY - 2002 DO - https://doi.org/10.1016/S1293-2558(01)01193-1 SN - 1293-2558 SN - 1873-3085 VL - 4 IS - 1 SP - 109 EP - 115 PB - Elsevier CY - Amsterdam AN - OPUS4-1311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Witke, Klaus A1 - Feist, M. A1 - Troyanov, S.I. A1 - Kemnitz, E. T1 - Halogenometallate von Übergangselementen mit Kationen stickstoffhaltiger heterozyklischer Basen. VII Zwei Oxidationsstufen und vier verschiedene Koordinationen von Eisen in einer Verbindung. Synthese, Kristallstruktur und spektroskopische Charakterisierung von 1,4-Dimethylpiperazinium-Chloroferrat(II, III), (dmpipzH2)6[FeIICl4]2[FeIIICl4]2[FeIICl5] [FeIIICl6] JF - Zeitschrift für anorganische und allgemeine Chemie = Journal of inorganic and general chemistry KW - Halogenometallate KW - Spektroskopische Charakterisierung PY - 1999 SN - 0044-2313 SN - 1521-3749 SN - 0372-7874 SN - 0863-1786 SN - 0863-1778 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 625 IS - 1 SP - 141 EP - 146 PB - Wiley-VCH CY - Weinheim AN - OPUS4-738 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Zakharchuk, N. F. A1 - Stößer, R. A1 - Schroder, U. A1 - Scholz, F. T1 - Solid state electrochemistry, X-ray powder diffraction, magnetic susceptibility, electron spin resonance, Mössbauer and diffuse reflectance spectroscopy of mixed iron(III)-cadmium(II) hexacyanoferrates JF - Journal of solid state electrochemistry KW - Festkörper KW - Elektrochemie KW - Mössbauer KW - Suszeptibilität KW - Magnetisierungskoeffizient PY - 1999 SN - 1432-8488 SN - 1433-0768 IS - 3 SP - 264 EP - 276 PB - Springer CY - Berlin AN - OPUS4-713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maltsev, Y. A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Rogozev, B. T1 - Precision in Mössbauer Spectroscopy JF - Hyperfine Interactions 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 - Feist, M. A1 - Troyanov, S.I. A1 - Mehner, Hartmut A1 - Witke, Klaus A1 - Kemnitz, E. T1 - Zwei Oxidationsstufen und vier verschiedene Koordinationen von Eisen in einer Verbindung. Synthese, Kristallstruktur und spektroskopische Charakterisierung von 1,4-Dimethylpiperazinium-Chloroferrat(II, III), (dmpipzH2)6[FeIICl4]2[FeIIICl4]2[FeIICl5] [FeIIICl6] JF - Zeitschrift für anorganische und allgemeine Chemie = Journal of inorganic and general chemistry KW - 1,4-Dimethylpiperazinium chloroferrate(II,III) KW - Crystal Structure KW - Trigonal-bipyramidal pentachloroferrate(II) KW - Mössbauer, Raman spectroscopy PY - 1999 SN - 0044-2313 SN - 1521-3749 SN - 0372-7874 SN - 0863-1786 SN - 0863-1778 IS - 625 SP - 141 EP - 146 PB - Wiley-VCH CY - Weinheim AN - OPUS4-2305 LA - deu 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 JF - Hyperfine Interactions 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 - JOUR A1 - Witke, Klaus A1 - Kunze, Ralf A1 - Neubert, Dietmar A1 - Mehner, Hartmut A1 - Feist, M. A1 - Kemnitz, E. T1 - Two oxidation states and four different coordinations of iron in an unusual chloro complex: TG-MS, Raman and Mössbauer spectroscopic investigations of the thermal behaviour JF - Thermochimica Acta N2 - Conventional simultaneous thermal analysis, capillary-coupled TG–MS, in situ and ex situ Raman and Mössbauer spectroscopy, as well as chemical analysis have been used for the investigation of the first decomposition step of the mixed valence chloroferrate (dmpipzH2)6[Fe(II)Cl4]2[Fe(III)Cl4]2[Fe(II)Cl5][Fe(III)Cl6]. Under argon at ca. 200°C, an almost complete reduction proceeds in a solid state reaction forming Fe(II). It is accompanied by the release of HCl and, to a minor degree, carbon containing species. A multi-phase product with at least two chloroferrate species, coke, and C,H,N-containing polymers is formed. Binuclear iron complexes, such as (dmpipzH)2[Fe(II)2Cl6], and small amounts of (dmpipzH)[Fe(III)Cl4] have been proposed to be the major and minor component of the product mixture, respectively. KW - Mixed valence chloroferrate KW - Thermal decomposition KW - Intramolecular reduction PY - 2000 DO - https://doi.org/10.1016/S0040-6031(00)00546-3 SN - 0040-6031 SN - 1872-762X VL - 361 IS - 1-2 SP - 53 EP - 60 PB - Elsevier CY - Amsterdam AN - OPUS4-988 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 JF - Surface and coatings technology 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 - Mehner, Hartmut A1 - Menzel, Michael A1 - Weber, K. A1 - Regener, D. T1 - Characterization of the microstructure of high-chromium cast irons using Mössbauer spectroscopy JF - Materials characterization 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 - Pitsch, I. A1 - Geßner, W. A1 - Brückner, A. A1 - Möhmel, St. A1 - Uecker, D.-Ch. A1 - Pohl, M.-M. T1 - Synthesis and characterization of Fe2O3 containing aluminas by thermal decomposition of modified ammonium dawsonite JF - Journal of materials chemistry N2 - Aluminas with Fe2O3 particles finely divided in the Al2O3 matrix were prepared via a crystalline precursor derived from ammonium dawsonite and its calcination. The precursors with Fe content between 1 and 10 wt% were synthesized by reaction of ammonium hydrogen carbonate with mixtures containing aluminium ammonium sulfate and ferric ammonium sulfate. The characterization of the as-synthesized and calcined products by chemical analysis, XRD, EPR, Mössbauer, TEM and adsorption measurements shows that all the Fe3+ ions are incorporated into the structure of dawsonite when the Fe content is low and that the calcined materials with micropores and mesopores (maximum 30–40 Å) also contain very small Fe2O3 particles (<10 nm) at higher Fe contents. PY - 2001 DO - https://doi.org/10.1039/b101466h SN - 0959-9428 SN - 1364-5501 IS - 11 SP - 2498 EP - 2503 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-1206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mehner, Hartmut A1 - Berndt, H. A1 - Menzel, Michael T1 - Mössbauer Studies of noble metal / tin catalysts used for selective hydrogenation T2 - 4th Seeheim Workshop on Mössbauer Spectroscopy T2 - 4th Seeheim Workshop on Mössbauer Spectroscopy CY - Seeheim-Jugenheim, Germany DA - 1994-05-24 PY - 1994 AN - OPUS4-6222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mehner, Hartmut A1 - Berndt, H. A1 - Claus, P. A1 - Menzel, Michael T1 - Mössbauer Studies of noble metal catalysts promoted by tin T2 - ICAME'97 Conference T2 - ICAME'97 Conference CY - Rio de Janeiro, Brazil DA - 1997-09-14 PY - 1997 AN - OPUS4-6225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasten, C. A1 - Carl, G. A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Rüssel, C. T1 - Polyvalent Ions - Their Behaviour in the Glass Melt and their Influence on Glass Crystallisation JF - Molten salt forum KW - Polyvalent Ions KW - Redox State KW - Mössbauer Spectroscopy KW - Glass Crystallisation KW - Microstructure PY - 1998 SN - 1021-6138 VL - 5-6 SP - 555 EP - 558 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-6931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehner, Hartmut A1 - Menzel, Michael A1 - Berndt, H. A1 - Claus, P. T1 - Mössbauer studies of platinum and rhodium catalysts promoted by tin JF - Hyperfine Interactions T2 - International Conference on Applications of the Mössbauer Effect (ICAME '97) ; in memoriam of Professor Jacques CY - Rio de Janeiro, Brazil DA - 1997-09-14 PY - 1998 SN - 0304-3843 SN - 1572-9540 VL - 113 IS - 1-4 SP - 92 EP - 95 PB - Kluwer CY - Dordrecht AN - OPUS4-6932 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 - Hyperfine interactions (C) 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 - 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 JF - Hyperfine Interactions 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 -