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Fast Mapping of the Cobalt-Valence State in Ba0.5Sr0.5Co0.8Fe0.2O3-d by Electron Energy Loss Spectroscopy

Published online by Cambridge University Press:  16 October 2013

Philipp Müller*
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany Karlsruher Institut für Technologie (KIT), DFG-Center for Functional Nanostructures (CFN), 76131 Karlsruhe, Germany
Matthias Meffert
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany
Heike Störmer
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany
Dagmar Gerthsen
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany Karlsruher Institut für Technologie (KIT), DFG-Center for Functional Nanostructures (CFN), 76131 Karlsruhe, Germany
*
*Corresponding author.philipp.mueller@kit.edu
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Abstract

A fast method for determination of the Co-valence state by electron energy loss spectroscopy in a transmission electron microscope is presented. We suggest the distance between the Co-L3 and Co-L2 white-lines as a reliable property for the determination of Co-valence states between 2+ and 3+. The determination of the Co-L2,3 white-line distance can be automated and is therefore well suited for the evaluation of large data sets that are collected for line scans and mappings. Data with a low signal-to-noise due to short acquisition times can be processed by applying principal component analysis. The new technique was applied to study the Co-valence state of Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF), which is hampered by the superposition of the Ba-M4,5 white-lines on the Co-L2,3 white-lines. The Co-valence state of the cubic BSCF phase was determined to be 2.2+ (±0.2) after annealing for 100 h at 650°C, compared to an increased valence state of 2.8+ (±0.2) for the hexagonal phase. These results support models that correlate the instability of the cubic BSCF phase with an increased Co-valence state at temperatures below 840°C.

Type
Materials Applications
Copyright
Copyright © Microscopy Society of America 2013 

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References

Abbate, M., Fuggle, J.C., Fujimori, A., Tjeng, L.H., Chen, C.T., Potze, R., Sawatzky, G.A., Eisaki, H. & Uchida, S. (1993). Electronic structure and spin-state transition of LaCoO3 . Phys Rev B Condens Matter 47, 1612416130.CrossRefGoogle ScholarPubMed
Ahn, C.C. (2004). Transmission Electron Energy Loss Spectrometry in Materials Science and The EELS Atlas. Weinheim, Germany: Wiley-VCH.Google Scholar
Arnold, M., Gesing, T.M., Martynczuk, J. & Feldhoff, A. (2008). Correlation of the formation and the decomposition process of the BSCF perovskite at intermediate temperatures. Chem Mater 20, 58515858.Google Scholar
Arnold, M., Wang, H., Martynczuk, J. & Feldhoff, A. (2007). In situ study of the reaction sequence in sol-gel synthesis of a (Ba0.5Sr0.5)(Co0.8Fe0.2)O3-d perovskite by X-ray diffraction and transmission electron microscopy. Commun Am Ceram Soc 90, 36513655.Google Scholar
Arnold, M., Xu, Q., Tichelaar, F.D. & Feldhoff, A. (2009). Local charge disproportion in a high-performance perovskite. Chem Mater 21, 635640.Google Scholar
Bouwmeester, H.J.M. & Burggraaf, A.J. (1997). The CRC Handbook of Solid State Electrochemistry (Chapter 14). Boca Raton, FL: CRC Press.Google Scholar
Cliff, G. & Lorimer, G.W. (1975). The quantitative analysis of thin specimens. J Microsc 103, 203207.Google Scholar
Crewe, A.V. (1966). Scanning electron microscopes: Is high resolution possible? Science 154, 729738.CrossRefGoogle ScholarPubMed
Crewe, A.V., Wall, J. & Welter, L.M. (1968). A high-resolution scanning transmission electron microscope. J Appl Phys 39, 58615868.Google Scholar
Czyperek, M., Zapp, P., Bouwmeester, H.J.M., Modigell, M., Ebert, K., Voigt, I., Meulenberg, W.A., Singheiser, L. & Stöver, D. (2010). Gas separation membranes for zero-emission fossil power plants: MEM-BRAIN. J Memb Sci 359, 149159.Google Scholar
David, R., Pautrat, A., Kabbour, H., Sturza, M., Curelea, S., André, G., Pelloquin, D. & Mentré, O. (2011). [BaCoO3] n [BaCo8O11] Modular intergrowths: Singularity of the n = 2 Term. Chem Mater 23, 51915199.CrossRefGoogle Scholar
de Groot, F. (2005). Multiplet effects in X-ray spectroscopy. Coord Chem Rev 249, 3163.Google Scholar
de Groot, F.M.F. (1994). X-ray absorption and dichroism of transition metals and their compounds. J Electron Spectrosc Relat Phenomena 67, 529622.Google Scholar
de Groot, F.M.F., Abbate, M., van Elp, J., Sawatzky, G.A., Ma, Y.J., Chen, C.T. & Sette, F. (1993). Oxygen 1s and cobalt 2p X-ray absorption of cobalt oxides. J Phys Condens Matter 5, 2277. Google Scholar
Efimov, K., Xu, Q. & Feldhoff, A. (2010). Transmission electron microscopy study of Ba0.5Sr0.5Co0.8Fe0.2O3-d perovskite decomposition at intermediate temperatures. Chem Mater 22, 58665875.Google Scholar
Fink, J., Müller-Heinzerling, T., Scheerer, B., Speier, W., Hillebrecht, F.U., Fuggle, J.C., Zaanen, J. & Sawatzky, G.A. (1985). 2p absorption spectra of the 3d elements. Phys Rev B Condens Matter 32, 48994904.Google Scholar
Harvey, A.S., Litterst, F.J., Yang, Z., Rupp, J.L.M., Infortuna, A. & Gauckler, L.J. (2009a). Oxidation states of Co and Fe in Ba1−x Sr x Co1−y Fe y O3−d (x,y = 0.2–0.8) and oxygen desorption in the temperature range 300–1273 K. Phys Chem 11, 30903098.Google Scholar
Harvey, A.S., Yang, Z., Infortuna, A., Beckel, D., Purton, J.A. & Gauckler, L.J. (2009b). Development of electron holes across the temperature-induced semiconductor–metal transition in Ba1−x Sr x Co1−y Fe y O3−d (x,y = 0.2–0.8): A soft X-ray absorption spectroscopy study. J Phys Condens Matter 21, 015801. Google Scholar
Hashim, S.M., Mohamed, A.R. & Bhatia, S. (2010). Current status of ceramic-based membranes for oxygen separation from air. Adv Colloid Interface Sci 160, 88100.Google Scholar
Haworth, P., Smart, S., Glasscock, J. & da Costa, J.C.D. (2011). Yttrium doped BSCF membranes for oxygen separation. Sep Purif Technol 81, 8893.CrossRefGoogle Scholar
Haworth, P., Smart, S., Glasscock, J. & da Costa, J.C.D. (2012). High performance yttrium-doped BSCF hollow fibre membranes. Sep Purif Technol 94, 1622.CrossRefGoogle Scholar
Horita, Z., Sano, T. & Nemoto, M. (1986). An extrapolation method for the determination of Cliff-Lorimer kAB factors at zero foil thickness. J Microsc 143, 215231.Google Scholar
Hotelling, H. (1933). Analysis of a complex of statistical variables into principal components. J Educ Psychol 24, 417441.Google Scholar
Kriegel, R., Kircheisen, R. & Töpfer, J. (2010). Oxygen stoichiometry and expansion behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-d . Solid State Ionics 181, 6470.CrossRefGoogle Scholar
Leapman, R.D. & Grunes, L.A. (1980). Anomalous L3/L2 white-line ratios in the 3d transition metals. Phys Rev Lett 45, 397401.Google Scholar
Leapman, R.D. & Swyt, C.R. (1988). Separation of overlapping core edges in electron energy loss spectra by multiple-least-squares fitting. Ultramicroscopy 26, 393403.Google Scholar
Leo, A., Liu, S. & da Costa, J.C.D. (2009). Development of mixed conducting membranes for clean coal energy delivery. Int J Greenhouse Gas Control 3, 357367.CrossRefGoogle Scholar
Liu, Y., Tan, X. & Li, K. (2006). Mixed conducting ceramics for catalytic membrane processing. Catalysis Rev: Sci Eng 48, 145198.Google Scholar
Miranda, A., Borgne, Y.-A. & Bontempi, G. (2008). New routes from minimal approximation error to principal components. Neural Process Lett 27, 197207.CrossRefGoogle Scholar
Mitterbauer, C., Kothleitner, G., Grogger, W., Zandbergen, H., Freitag, B., Tiemeijer, P. & Hofer, F. (2003). Electron energy-loss near-edge structures of 3d transition metal oxides recorded at high-energy resolution. Ultramicroscopy 96, 469480.CrossRefGoogle ScholarPubMed
Mueller, D.N., Souza, R.A.D., Weirich, T.E., Roehrens, D., Mayer, J. & Martin, M. (2010). A kinetic study of the decomposition of the cubic perovskite-type oxide Ba x Sr1−x Co0.8Fe0.2O3−d (BSCF) (x = 0.1 and 0.5). Phys Chem Chem Phys 12, 1032010328.Google Scholar
Müller, P., Dieterle, L., Müller, E., Störmer, H., Gerthsen, D., Niedrig, C., Taufall, S., Wagner, S.F. & Ivers-Tiffee, E. (2010). Ba0.5Sr0.5Co0.8Fe0.2O3-d for oxygen separation membranes. ECS Trans 28, 309314.CrossRefGoogle Scholar
Müller, P., Störmer, H., Dieterle, L., Niedrig, C., Ivers-Tiffée, E. & Gerthsen, D. (2012). Decomposition pathway of cubic Ba0.5Sr0.5Co0.8Fe0.2O3-d between 700°C and 1000°C analyzed by electron microscopic techniques. Solid State Ionics 206, 5766.Google Scholar
Müller, P., Störmer, H., Meffert, M., Dieterle, L., Niedrig, C., Wagner, S.F., Ivers-Tiffée, E. & Gerthsen, D. (2013). Secondary phase formation in Ba0.5Sr0.5Co0.8Fe0.2O3-d studied by electron microscopy. Chem Mater 25(4), 564573.Google Scholar
Niedrig, C., Taufall, S., Burriel, M., Menesklou, W., Wagner, S.F., Baumann, S. & Ivers-Tiffée, E. (2011). Thermal stability of the cubic phase in Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF). Solid State Ionics 197, 2531.Google Scholar
Pearson, D.H., Ahn, C.C. & Fultz, B. (1993). White lines and d-electron occupancies for the 3d and 4d transition metals. J Phys Condens Matter 47, 84718478.Google ScholarPubMed
Shannon, R.D. (1976). Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr Sect A 32, 751767.Google Scholar
Shao, Z., Yang, W., Cong, Y., Dong, H., Tong, J. & Xiong, G. (2000). Investigation of the permeation behavior and stability of a Ba0.5Sr0.5Co0.8Fe0.2O3−d oxygen membrane. J Membr Sci 172, 177188.Google Scholar
Shuman, H. & Somlyo, A.P. (1987). Electron energy loss analysis of near-trace-element concentrations of calcium. Ultramicroscopy 21, 2332.Google Scholar
Sun, J., Yang, M., Li, G., Yang, T., Liao, F., Wang, Y., Xiong, M. & Lin, J. (2006). New barium cobaltite series Ba n+1Co n O3n+3(Co8O8): Intergrowth structure containing perovskite and CdI2-type layers. Inorg Chem 45, 91519153.Google Scholar
Sunarso, J., Baumann, S., Serra, J.M., Meulenberg, W.A., Liu, S., Lin, Y.S. & da Costa, J.C.D. (2008). Mixed ionic-electronic conducting (MIEC) ceramic-based membranes for oxygen separation. J Membr Sci 320, 1341.Google Scholar
Svarcová, S., Wiik, K., Tolchard, J., Bouwmeester, H.J.M. & Grande, T. (2008). Structural instability of cubic perovskite Ba x Sr1−x Co1−y Fe y O3−d . Solid State Ionics 178, 17871791.Google Scholar
Tan, H., Verbeeck, J., Abakumov, A. & Van Tendeloo, G. (2012). Oxidation state and chemical shift investigation in transition metal oxides by EELS. Ultramicroscopy 116, 2433.CrossRefGoogle Scholar
van der Laan, G. & Kirkman, I.W. (1992). The 2p absorption spectra of 3d transition metal compounds in tetrahedral and octahedral symmetry. J Phys Condens Matter 4, 4189. Google Scholar
Wall, J., Langmore, J., Isaacson, M. & Crewe, A.V. (1974). Scanning transmission electron microscopy at high resolution. Proc Natl Acad Sci 71, 15.CrossRefGoogle ScholarPubMed
Wang, Z.L., Bentley, J. & Evans, N.D. (2000a). Valence state mapping of cobalt and manganese using near-edge fine structures. Micron 31, 355362.Google Scholar
Wang, Z.L., Yin, J.S. & Jiang, Y.D. (2000b). EELS analysis of cation valence states and oxygen vacancies in magnetic oxides. Micron 31, 571580.Google Scholar
Yakovlev, S., Yoo, C.-Y., Fang, S. & Bouwmeester, H.J.M. (2010). Phase transformation and oxygen equilibration kinetics of pure and Zr-doped Ba0.5Sr0.5Co0.8Fe0.2O3−d perovskite oxide probed by electrical conductivity relaxation. Appl Phys Lett 96, 254101. Google Scholar