TY - JOUR
T1 - Anomalous oxidation states in multilayers for fuel cell applications
AU - Perkins, James M.
AU - Fearn, Sarah
AU - Cook, Stuart N.
AU - Srinivasan, Rajagopalan
AU - Rouleau, Chris M.
AU - Christen, Hans M.
AU - West, Geoff D.
AU - Morris, Richard J.H.
AU - Fraser, Hamish L.
AU - Skinner, Stephen J.
AU - Kilner, John A.
AU - McComb, David W.
PY - 2010/8/23
Y1 - 2010/8/23
N2 - Significant recent interest has been directed towards the relationship between interfaces and reports of enhanced ionic conductivity. To gain a greater understanding of the effects of hetero-interfaces on ionic conductivity, advanced analytical techniques including electron microscopy (TEM/STEM), electron energy loss spectroscopy (EELS), and secondary ion mass spectrometry (SIMS) are used to characterize CeO2/Ce0.85Sm 0.15O2 multilayer thin films grown by pulsed laser deposition. High quality growth is observed, but ionic conductivity measured by impedance spectroscopy and 18O tracer experiments is consistent with bulk materials. EELS analysis reveals the unusual situation of layers containing only Ce(IV) adjacent to layers containing both Ce(III) and Ce(IV). Post oxygen annealing induced oxygen diffusion and mixed oxidation states in both layers, but only in the vicinity of low angle grain boundaries perpendicular to the layers. The implications of the anomalous behavior of the Ce oxidation states on the design of novel electrolytes for solid oxide fuel cells is discussed.
AB - Significant recent interest has been directed towards the relationship between interfaces and reports of enhanced ionic conductivity. To gain a greater understanding of the effects of hetero-interfaces on ionic conductivity, advanced analytical techniques including electron microscopy (TEM/STEM), electron energy loss spectroscopy (EELS), and secondary ion mass spectrometry (SIMS) are used to characterize CeO2/Ce0.85Sm 0.15O2 multilayer thin films grown by pulsed laser deposition. High quality growth is observed, but ionic conductivity measured by impedance spectroscopy and 18O tracer experiments is consistent with bulk materials. EELS analysis reveals the unusual situation of layers containing only Ce(IV) adjacent to layers containing both Ce(III) and Ce(IV). Post oxygen annealing induced oxygen diffusion and mixed oxidation states in both layers, but only in the vicinity of low angle grain boundaries perpendicular to the layers. The implications of the anomalous behavior of the Ce oxidation states on the design of novel electrolytes for solid oxide fuel cells is discussed.
UR - https://www.scopus.com/pages/publications/77956039083
U2 - 10.1002/adfm.201000279
DO - 10.1002/adfm.201000279
M3 - Article
AN - SCOPUS:77956039083
SN - 1616-301X
VL - 20
SP - 2664
EP - 2674
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 16
ER -