Influence of B-site doping with Ti and Nb on microstructure and phase constitution of (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ
Source abstract
Abstract
(Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ (BSCF) with mixed ionic and electronic conductivity is promising as oxygen separation membrane. However, its exceptional oxygen permeability is linked to the cubic perovskite phase, which destabilizes below 825 °C. This work is concerned with the stabilizing effect of partial B-site substitution in BSCF by Ti (10%) and Nb (5% and 10%). In addition, the effect of B-site substoichiometry on the formation of CoO precipitates as nucleation sites for other secondary phases is studied. The focus of this work is laid on the analysis of the phase constitution in bulk material between 600 and 800 °C. Scanning electron microscopy and (scanning) transmission electron microscopy with high spatial resolution in combination with energy-dispersive X-ray spectroscopy are applied which allow to detect even small volume fractions of secondary phases. It is confirmed by quantitative analysis that Ti and Nb substitution reduces the formation of secondary phases up to ~ 95%. There is a solubility limit of Nb in BSCF, which leads to the precipitation of Nb-rich precipitates already at 5% Nb substitution in contrast to Ti which is fully soluble even at 10% substitution. Despite of that, BSCF doped with 5% Nb in combination with 5% substoichiometric B-site occupation is the most promising material, because it shows the lowest overall volume fraction of secondary phases (~ 0.8 vol% at 700 °C) and an almost negligible degradation rate in additionally recorded long-term resistivity measurements.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Advancements in Solid Oxide Fuel Cells · Magnetic and transport properties of perovskites and related materials · Electronic and Structural Properties of Oxides
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (37)
Show source-provided references
1. 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−δ oxygen membrane. J Membr Sci 172(1–2):177–18810.1016/S0376-7388(00)00337-9 ↗
2. McIntosh S, Vente JF, Haije WG, Blank DHA, Bouwmeester HJM (2006) Structure and oxygen stoichiometry of SrCo0.8Fe0.2O3−δ and Ba0.5Sr0.5Co0.8Fe0.2O3−δ. Solid State Ionics 177(19–25):1737–174210.1016/j.ssi.2006.03.041 ↗
3. Zeng P, Chen Z, Zhou W, Gu H, Shao Z, Liu S (2007) Re-evaluation of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite as oxygen semi-permeable membrane. J Membr Sci 291(1–2):148–15610.1016/j.memsci.2007.01.003 ↗
4. Shao Z, Haile SM (2004) A high-performance cathode for the next generation of solid-oxide fuel cells. Nature 431(7005):170–17310.1038/nature02863 ↗
5. Liu QL, Khor KA, Chan SH (2006) High-performance low-temperature solid oxide fuel cell with novel BSCF cathode. J Power Sources 161(1):123–12810.1016/j.jpowsour.2006.03.095 ↗
6. Švarcová S, Wiik K, Tolchard J, Bouwmeester HJM, Grande T (2008) Structural instability of cubic perovskite BaxSr1−xCo1−yFeyO3−δ. Solid State Ionics 178(35–36):1787–179110.1016/j.ssi.2007.11.031 ↗
7. Niedrig C, Taufall S, Burriel M, Menesklou W, Wagner SF, Baumann S, Ivers-Tiffée E (2011) Thermal stability of the cubic phase in Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF)1. Solid State Ionics 197(1):25–3110.1016/j.ssi.2011.06.010 ↗
8. Müller P, Störmer H, Dieterle L, Niedrig C, Ivers-Tiffée E, Gerthsen D (2012) Decomposition pathway of cubic Ba0.5Sr0.5Co0.8Fe0.2O3−δ between 700°C and 1000°C analyzed by electron microscopic techniques. Solid State Ionics 206:57–6610.1016/j.ssi.2011.10.013 ↗
9. Mueller DN, de Souza RA, Weirich TE, Roehrens D, Mayer J, Martin M (2010) A kinetic study of the decomposition of the cubic perovskite-type oxide BaxSr1−xCo0.8Fe0.2O3−delta (BSCF) (x = 0.1 and 0.5). Phys Chem Chem Phys 12(35):10320–1032810.1039/c0cp00004c ↗
10. Arnold M, Gesing TM, Martynczuk J, Feldhoff A (2008) Correlation of the formation and the decomposition process of the BSCF perovskite at intermediate temperatures. Chem Mater 20(18):5851–585810.1021/cm801463h ↗
11. Sun J, Yang M, Li G, Yang T, Liao F, Wang Y, Xiong M, Lin J (2006) New barium cobaltite series Ban+1ConO3n+3(Co8O8): intergrowth structure containing perovskite and CdI2-type layers. Inorg Chem 45(23):9151–915310.1021/ic060992v ↗
12. Müller P, Störmer H, Meffert M, Dieterle L, Niedrig C, Wagner SF, Ivers-Tiffée E, Gerthsen D (2013) Secondary phase formation in Ba0.5Sr0.5Co0.8Fe0.2O3−δ studied by electron microscopy. Chem Mater 25(4):564–57310.1021/cm303670m ↗
13. Efimov K, Xu Q, Feldhoff A (2010) Transmission electron microscopy study of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite decomposition at intermediate temperatures. Chem Mater 22(21):5866–587510.1021/cm101745v ↗
14. Meffert M, Unger L-S, Störmer H, Sigloch F, Wagner SF, Ivers-Tiffée E, Gerthsen D (2019) The effect of B-site Y substitution on cubic phase stabilization in (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ. J Am Ceram Soc 102(8):4929–494210.1111/jace.16343 ↗
15. Chen M, Hallstedt B, Gauckler LJ (2003) Thermodynamic assessment of the Co–O system. JPE 24(3):212–22710.1361/105497103770330514 ↗
16. Meffert M, Unger L-S, Grünewald L, Störmer H, Wagner SF, Ivers-Tiffée E, Gerthsen D (2017) The impact of grain size, A/B-cation ratio, and Y-doping on secondary phase formation in (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ. J Mater Sci 52(5):2705–2719. https://doi.org/10.1007/s10853-016-0562-810.1007/s10853-016-0562-8 ↗
17. Arnold M, Xu Q, Tichelaar FD, Feldhoff A (2009) Local charge disproportion in a high-performance perovskite. Chem Mater 21(4):635–64010.1021/cm802779f ↗
18. Harvey AS, Litterst FJ, Yang Z, Rupp JLM, Infortuna A, Gauckler LJ (2009) Oxidation states of Co and Fe in Ba1−xSrxCo1−yFeyO3−delta (x, y = 0.2–0.8) and oxygen desorption in the temperature range 300–1273 K. Phys Chem Chem Phys 11(17):3090–309810.1039/b819414a ↗
19. Müller P, Meffert M, Störmer H, Gerthsen D (2013) Fast mapping of the cobalt-valence state in Ba0.5Sr0.5Co0.8Fe0.2O3−δ by electron energy loss spectroscopy. Microsc Microanal 19(6):1595–160510.1017/S1431927613013536 ↗
20. Shannon RD (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Cryst A 32(5):751–76710.1107/S0567739476001551 ↗
21. Haworth P, Smart S, Glasscock J, Diniz da Costa JC (2011) Yttrium doped BSCF membranes for oxygen separation. Sep Purif Technol 81(1):88–9310.1016/j.seppur.2011.07.007 ↗
22. Yakovlev S, Yoo C-Y, Fang S, Bouwmeester HJM (2010) Phase transformation and oxygen equilibration kinetics of pure and Zr-doped Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite oxide probed by electrical conductivity relaxation. Appl Phys Lett 96(25):254101–25410310.1063/1.3455908 ↗
23. Nagai T, Ito W, Sakon T (2007) Relationship between cation substitution and stability of perovskite structure in SrCoO3−δ-based mixed conductors. Solid State Ionics 177(39–40):3433–344410.1016/j.ssi.2006.10.022 ↗
24. Goodenough JB, Kafalas JA (1973) Exploring the A+B5+O3 compounds. J Solid State Chem 6(4):493–50110.1016/S0022-4596(73)80005-2 ↗
25. Fang SM, Yoo C-Y, Bouwmeester HJM (2011) Performance and stability of niobium-substituted Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes. Solid State Ionics 195(1):1–610.1016/j.ssi.2011.05.022 ↗
26. Bi L, Fabbri E, Traversa E (2012) Novel Ba0.5Sr0.5(Co0.8Fe0.2)1−xTixO3−δ (x = 0, 0.05, and 0.1) cathode materials for proton-conducting solid oxide fuel cells. Solid State Ionics 214:1–510.1016/j.ssi.2012.02.049 ↗
27. Wang F, Nakamura T, Yashiro K, Mizusaki J, Amezawa K (2014) Effect of Nb doping on the chemical stability of BSCF-based solid solutions. Solid State Ionics 262:719–72310.1016/j.ssi.2014.01.045 ↗
28. Egorova YV, Scherb T, Schumacher G, Bouwmeester HJM, Filatova EO (2015) Soft X-ray absorption spectroscopy study of (Ba0.5Sr0.5)(Co0.8Fe0.2)1−xNbxO3−δ with different content of Nb (5%–20%). J Alloys Compd 650:848–85210.1016/j.jallcom.2015.08.073 ↗
29. Meffert M, Störmer H, Gerthsen D (2016) Dopant-site determination in Y- and Sc-doped (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ by atom location by channeling enhanced microanalysis and the role of dopant site on secondary phase formation. Microsc Microanal 22(1):113–12110.1017/S1431927615015536 ↗
30. Stadelmann P (2003) Image analysis and simulation software in transmission electron microscopy. Microsc Microanal 9(S03):60–6110.1017/S1431927603012224 ↗
31. Ting V, Liu Y, Norén L, Withers RL, Goossens DJ, James M, Ferraris C (2004) A structure, conductivity and dielectric properties investigation of A3CoNb2O9 (A = Ca2+, Sr2+, Ba2+) triple perovskites. J Solid State Chem 177(12):4428–444210.1016/j.jssc.2004.09.016 ↗
32. Yoshii K (2000) Magnetic transition in the perovskite Ba2CoNbO6. J Solid State Chem 151(2):294–29710.1006/jssc.2000.8656 ↗
33. Arnold M, Wang H, Feldhoff A (2007) Influence of CO2 on the oxygen permeation performance and the microstructure of perovskite-type (Ba0.5Sr0.5)(Co0.8Fe0.2)O3−δ membranes. J Membr Sci 293(1–2):44–5210.1016/j.memsci.2007.01.032 ↗
34. Yan A, Maragou V, Arico A, Cheng M, Tsiakaras P (2007) Investigation of a Ba0.5Sr0.5Co0.8Fe0.2O3−δ based cathode SOFC II. The effect of CO2 on the chemical stability. Appl Catal B 76(3–4):320–32710.1016/j.apcatb.2007.06.010 ↗
35. Yi J, Schroeder M, Weirich T, Mayer J (2010) Behavior of Ba(Co, Fe, Nb)O3−δ perovskite in CO2-containing atmospheres: degradation mechanism and materials design. Chem Mater 22(23):6246–625310.1021/cm101665r ↗
36. Almar L, Störmer H, Meffert M, Szász J, Wankmüller F, Gerthsen D, Ivers-Tiffée E (2018) Improved phase stability and CO2 poisoning robustness of Y-doped Ba0.5Sr0.5Co0.8Fe0.2O3−δ SOFC cathodes at intermediate temperatures. ACS Appl. Energy Mater. 1(3):1316–132710.1021/acsaem.8b00028 ↗
37. Jeong NC, Lee JS, Tae EL, Lee YJ, Yoon KB (2008) Acidity scale for metal oxides and Sanderson’s electronegativities of lanthanide elements. Angew Chem Int Ed Engl 47(52):10128–1013210.1002/anie.200803837 ↗