Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-13T13:01:44.749Z Has data issue: false hasContentIssue false

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
Get access

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 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

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