title: Toward tailorable surfaces: a combined theoretical and experimental study of lanthanum niobate layered perovskites.
abstract: A comprehensive theoretical investigation of the MLaNb2O7 (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 HLaNb2O7 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.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze ed. 17, I-90128 Palermo, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Di Tommaso
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze ed. 17, I-90128 Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Giannici
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze ed. 17, I-90128 Palermo, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Mossuto Marculescu
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze ed. 17, I-90128 Palermo, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Martorana
authors.affiliation: Institut de Recherche de Chimie de Paris CNRS Chimie ParisTech, 11, rue Pierre et Marie Curie, F-75005 Paris, France.
authors.forename: Carlo
authors.initials: C
authors.lastname: Adamo
authors.affiliation: Institut de Recherche de Chimie de Paris CNRS Chimie ParisTech, 11, rue Pierre et Marie Curie, F-75005 Paris, France.
authors.forename: Frédèric
authors.initials: F
authors.lastname: Labat