title: Beyond the structure-property relationship paradigm: influence of the crystal structure and microstructure on the Li+ conductivity of La2/3Li(x)Ti(1-x)Al(x)O3 Oxides.
abstract: The crystal structures of several oxides of the La(2/3)Li(x)Ti(1-x)Al(x)O(3) system have been studied by selected-area electron diffraction, high-resolution transmission electron microscopy, and powder neutron diffraction, and their lithium conductivity has been by complex impedance spectroscopy. The compounds have a perovskite-related structure with a unit cell radical2 a(p)x2 a(p)x radical2 a(p) (a(p)=perovskite lattice parameter) due to the tilting of the (Ti/Al)O(6) octahedra and the ordering of lanthanum and lithium ions and vacancies along the 2 a(p) axis. The Li(+) ions present a distorted square-planar coordination and are located in interstitial positions of the structure, which could explain the very high ionic conductivity of this type of material. The lithium conductivity depends on the oxide composition and its crystal microstructure, which varies with the thermal treatment of the sample. The microstructure of these titanates is complex due to formation of domains of ordering and other defects such as strains and compositional fluctuations.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias Químicas Universidad Complutense, 28040 Madrid, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: García-Martín
authors.forename: Ainhoa
authors.initials: A
authors.lastname: Morata-Orrantía
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Alario-Franco
authors.forename: Juan
authors.initials: J
authors.lastname: Rodríguez-Carvajal
authors.forename: Ulises
authors.initials: U
authors.lastname: Amador
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D003460:Crystallization; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010087:Oxides / Q000737:chemistry; D013329:Structure-Activity Relationship; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D028581:Lanthanoid Series Elements; D018020:Lithium Compounds; D010087:Oxides; C009495:titanium dioxide; D014025:Titanium; D000537:Aluminum Oxide