TY - JOUR
T1 - Cation Diffusion and Segregation at the Interface between Samarium-Doped Ceria and LSCF or LSFCu Cathodes Investigated with X-ray Microspectroscopy
AU - Giannici, Francesco
AU - Martorana, Antonino
AU - Aliotta, Chiara
AU - Canu, Giovanna
AU - Buscaglia, Vincenzo
AU - Longo, Alessandro
AU - Chiara, Alessandro
AU - Longo, Alessandro
AU - Gambino, Marianna
PY - 2017
Y1 - 2017
N2 - The chemical compatibility between electrolytes and electrodes is an extremely important aspect governing the overall impedance of solid-oxide cells. Because these devices work at elevated temperatures, they are especially prone to cation interdiffusion between the cell components, possibly resulting in secondary insulating phases. In this work, we applied X-ray microspectroscopy to study the interface between a samarium-doped ceria (SDC) electrolyte and lanthanum ferrite cathodes (La0.4Sr0.6Fe0.8Cu0.2O3(LSFCu); La0.9Sr0.1Fe0.85Co0.15O3(LSCF)), at a submicrometric level. This technique allows to combine the information about the diffusion profiles of cations on the scale of several micrometers, together with the chemical information coming from space-resolved X-ray absorption spectroscopy. In SDC-LSCF bilayers, we find that the prolonged thermal treatments at 1150 °C bring about the segregation of samarium and iron in micrometer-sized perovskite domains. In both SDC-LSCF and SDC-LSFCu bilayers, cerium diffuses into the cathode perovskite lattice A-site as a reduced Ce3+cation, whereas La3+is easily incorporated in the ceria lattice, reaching 30 atom % in the ceria layer in contact with LSFCu.
AB - The chemical compatibility between electrolytes and electrodes is an extremely important aspect governing the overall impedance of solid-oxide cells. Because these devices work at elevated temperatures, they are especially prone to cation interdiffusion between the cell components, possibly resulting in secondary insulating phases. In this work, we applied X-ray microspectroscopy to study the interface between a samarium-doped ceria (SDC) electrolyte and lanthanum ferrite cathodes (La0.4Sr0.6Fe0.8Cu0.2O3(LSFCu); La0.9Sr0.1Fe0.85Co0.15O3(LSCF)), at a submicrometric level. This technique allows to combine the information about the diffusion profiles of cations on the scale of several micrometers, together with the chemical information coming from space-resolved X-ray absorption spectroscopy. In SDC-LSCF bilayers, we find that the prolonged thermal treatments at 1150 °C bring about the segregation of samarium and iron in micrometer-sized perovskite domains. In both SDC-LSCF and SDC-LSFCu bilayers, cerium diffuses into the cathode perovskite lattice A-site as a reduced Ce3+cation, whereas La3+is easily incorporated in the ceria lattice, reaching 30 atom % in the ceria layer in contact with LSFCu.
UR - http://hdl.handle.net/10447/266842
M3 - Article
VL - 9
SP - 44466
EP - 44477
JO - ACS APPLIED MATERIALS & INTERFACES
JF - ACS APPLIED MATERIALS & INTERFACES
SN - 1944-8244
ER -