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Title: Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites

A comprehensive theoretical investigation of the MLaNb{sub 2}O{sub 7} (M = H, Li, Na, K, Rb, and Cs) series of ion-exchangeable layered perovskite is presented. These perovskites are in particular interesting in view of their potential applications as inorganic supports for the design of new hybrid inorganic-organic proton conductors. In particular, their structural and electronic properties have been investigated by periodic calculations in the framework of Density Functional Theory, using different exchange-correlation functionals. A general very good agreement with the available experimental (XRD, NPD, and EXAFS) data has been found. The structure of the protonated HLaNb{sub 2}O{sub 7} form has also been further clarified and a new tetragonal space group is proposed for this compound, better reproducing the experimental cell parameters and yielding to a more realistic picture of the system. The electronic investigation highlighted that all the compounds considered are very similar to each other and that the interaction between interlayer cations and perovskite slabs is purely ionic, except for the proton that is, instead, covalently bound.
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [2]
  1. Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze ed. 17, I-90128 Palermo (Italy)
  2. Institut de Recherche de Chimie de Paris CNRS Chimie ParisTech, 11, rue Pierre et Marie Curie, F-75005 Paris (France)
  3. (France)
Publication Date:
OSTI Identifier:
22308782
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTROSCOPY; CATIONS; DENSITY FUNCTIONAL METHOD; FINE STRUCTURE; HYBRIDIZATION; INTERACTIONS; LANTHANUM; NIOBATES; PEROVSKITE; PROTONS; SPACE GROUPS; SURFACES; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY