TY - JOUR
T1 - Layered LaSrGa(3)O7-Based Oxide-Ion Conductors: Cooperative Transport Mechanisms and Flexible Structures
AU - Tealdi, C
AU - Mustarelli, P
AU - Islam, M Saiful
PY - 2010/11/23
Y1 - 2010/11/23
N2 - Novel melilite-type gallium-oxides are attracting attention as promising new oxide-ion conductors with potential use in clean energy devices such as solid oxide fuel cells. Here, an atomic-scale investigation of the LaSrGa3O7-based system using advanced simulation techniques provides valuable insights into the defect chemistry and oxide ion conduction mechanisms, and includes comparison with the available experimental data. The simulation model reproduces the observed complex structure composed of layers of corner-sharing GaO4 tetrahedra. A major finding is the first indication that oxide-ion conduction in La(1.5)4Sr(0.46)Ga(3)O(7.27) occurs through an interstitialcy or cooperative-type mechanism involving the concerted knock-on motion of interstitial and lattice oxide ions. A key feature for the transport mechanism and high ionic conductivity is the intrinsic flexibility of the structure, which allows considerable local relaxation and changes in Ga coordination.
AB - Novel melilite-type gallium-oxides are attracting attention as promising new oxide-ion conductors with potential use in clean energy devices such as solid oxide fuel cells. Here, an atomic-scale investigation of the LaSrGa3O7-based system using advanced simulation techniques provides valuable insights into the defect chemistry and oxide ion conduction mechanisms, and includes comparison with the available experimental data. The simulation model reproduces the observed complex structure composed of layers of corner-sharing GaO4 tetrahedra. A major finding is the first indication that oxide-ion conduction in La(1.5)4Sr(0.46)Ga(3)O(7.27) occurs through an interstitialcy or cooperative-type mechanism involving the concerted knock-on motion of interstitial and lattice oxide ions. A key feature for the transport mechanism and high ionic conductivity is the intrinsic flexibility of the structure, which allows considerable local relaxation and changes in Ga coordination.
UR - http://www.scopus.com/inward/record.url?scp=78649830911&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1002/adfm.201001137
U2 - 10.1002/adfm.201001137
DO - 10.1002/adfm.201001137
M3 - Article
SN - 1616-301X
VL - 20
SP - 3874
EP - 3880
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 22
ER -