TY - JOUR A1 - Rades, Steffi A1 - Kraemer, S. A1 - Seshadri, R. A1 - Albert, B. T1 - Size and crystallinity dependence of magnetism in nanoscale iron boride, alpha-FeB N2 - A nanoscale boride, α-FeB, with grains of variable size and crystallinity was synthesized by precipitation from solution followed by heat treatment (450 °C, 550 °C, 750 °C, 1050 °C). Analysis of transmission electron micrographs, electron diffraction, and magnetic measurements suggests superparamagnetism at room temperature for the smaller, more disordered particles of FeB, while the larger, more crystalline particles of α-FeB, with a particle size of approximately 20 nm, display open magnetic hysteresis loops and blocking. In contrast to the soft ferromagnetism of bulk β-FeB, which was synthesized by conventional solid state reaction at 1500 °C, the sample of α-FeB annealed at 1050 °C is a harder ferromagnet, possibly due to stacking faults that pin the magnetic domains; these stacking faults are apparent in the high resolution transmission electron micrographs. The changes in magnetic behavior are visible from the varying blocking temperatures (63 K, 94 K, 150 K, and >320 K from the smallest to the largest particles) and correlate with the transformations from amorphous to α-FeB and from α-FeB to β-FeB. KW - Iron KW - Boride KW - Nano KW - Magnetism KW - Electron microscopy PY - 2014 DO - https://doi.org/10.1021/cm403167a SN - 0897-4756 SN - 1520-5002 VL - 26 IS - 4 SP - 1549 EP - 1552 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Esche, E. A1 - Kraemer, B. A1 - Müller, D. A1 - Meyer, Klas A1 - Zientek, Nicolai A1 - Maiwald, Michael A1 - Wozny, G. T1 - Improved desorption control via Raman spectroscopy N2 - In this contribution a Raman spectrometer based control structure for the heating of a desorption column is proposed. For this purpose calibration experiments for the absorption of carbon dioxide using monoethanolamine solutions are carried out and calibration models are developed to measure both carbon dioxide liquid loads and monoethanolamine mass fractions. The calibration experiments are supported by online NMR spectroscopy to accurately measure the appearance of all species in the electrolyte system. Both models are tested during the plant operation of a mini-plant for the oxidative coupling of methane and the proof of concept for the control structure is given. The Raman spectroscopy implemented in the ATEX conform mini-plant shows a reliable and robust performance being even indifferent to impurities hindering the GC analysis. T2 - 20th International Conference of Process Engineering and Chemical Plant Design CY - Berlin, Germany DA - 15.10.2014 KW - Absorption KW - Carbon capture KW - Raman spectroscopy KW - desorption control KW - Prozessanalytik KW - Process analytical technology PY - 2014 UR - https://www.verfahrenstechnik.tu-berlin.de/fileadmin/fg158/Dokumente/Manuskripte/2014/20th-ICPEPD-Proceedings.pdf SN - 978-3-00-047364-7 SP - 223 EP - 233 PB - Technische Universität Berlin CY - Berlin AN - OPUS4-37399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Klas A1 - Kraemer, B. A1 - Zientek, Nicolai A1 - Esche, E. A1 - Müller, D. A1 - Wozny, G. A1 - Maiwald, Michael T1 - Eine robuste Prozessanalytik für die Reaktivabsorption von CO2 aus industriellen Gasströmen basierend auf Online-NMR- und -Raman-Spektroskopie N2 - Die Abtrennung von CO2 aus industriellen Gasströmen ist eine großtechnisch wichtige Trennaufgabe. Neben der Aufarbeitung von Erdgas werden diese Verfahren zur Verminderung der CO2-Emission durch industrielle Rauchgase, insbesondere für alternativlose Prozesse wie die Stahl- und Zementproduktion diskutiert. T2 - 10. Kolloquium Arbeitskreis Prozessanalytik CY - Gerlingen, Germany DA - 25.11.2014 KW - Prozessanalytik KW - Quantitative NMR-Spektroskopie KW - Raman spectroscopy KW - CO2-Absorption KW - CCS PY - 2014 UR - http://arbeitskreis-prozessanalytik.de/images/stories/Veranstaltungen/Kolloquien/10_kolloquium_2014/tagungsband_10_kolloquium_ak_prozessanalytik_2014_hq-druck_f.pdf SP - P03, 23 EP - 23 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38359 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -