skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Abstract

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

Citation Formats

Di Tommaso, Stefania, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr, Giannici, Francesco, Mossuto Marculescu, Adriana, Martorana, Antonino, Adamo, Carlo, Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, and Labat, Frédèric, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr. Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites. United States: N. p., 2014. Web. doi:10.1063/1.4886338.
Di Tommaso, Stefania, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr, Giannici, Francesco, Mossuto Marculescu, Adriana, Martorana, Antonino, Adamo, Carlo, Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, & Labat, Frédèric, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr. Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites. United States. doi:10.1063/1.4886338.
Di Tommaso, Stefania, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr, Giannici, Francesco, Mossuto Marculescu, Adriana, Martorana, Antonino, Adamo, Carlo, Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, and Labat, Frédèric, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr. Mon . "Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites". United States. doi:10.1063/1.4886338.
@article{osti_22308782,
title = {Toward tailorable surfaces: A combined theoretical and experimental study of lanthanum niobate layered perovskites},
author = {Di Tommaso, Stefania, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr and Giannici, Francesco and Mossuto Marculescu, Adriana and Martorana, Antonino and Adamo, Carlo and Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris and Labat, Frédèric, E-mail: stefania.ditommaso@unipa.it, E-mail: frederic.labat@chimie-paristech.fr},
abstractNote = {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.},
doi = {10.1063/1.4886338},
journal = {Journal of Chemical Physics},
number = 2,
volume = 141,
place = {United States},
year = {Mon Jul 14 00:00:00 EDT 2014},
month = {Mon Jul 14 00:00:00 EDT 2014}
}
  • No abstract prepared.
  • The thermal stability and decomposition pathways of six Dion-Jacobson-related double-layered perovskites, ALaNb{sub 2}O{sub 7} (A = H, Li, Na, Ag) and (ACl)LaNb{sub 2}O{sub 7} (A = Fe, Cu), are investigated. These compounds are made by low temperature (<400 deg. C) ion exchange reactions from RbLaNb{sub 2}O{sub 7}. All the compounds are low temperature phases with some of them exhibiting decomposition exotherms consistent with metastability. Decomposition temperatures and reactions pathways vary with the identity of A with most decompositions resulting in the formation of a niobate (containing A) and LaNbO{sub 4}. Results from differential scanning calorimetry and high temperature X-ray powdermore » diffraction studies are presented and structural parameters pertinent to compound stability discussed.« less
  • The Dion–Jacobson double-layered perovskite, RbNdNb{sub 2}O{sub 7}, is used as a precursor to synthesize the series ANdNb{sub 2}O{sub 7} (A=H, Li, Na, K, NH{sub 4}, Ag), and (MCl)NdNb{sub 2}O{sub 7} (M=Mn, Fe, Cu) through ion-exchange reactions ≤400 °C. Thermal stability studies indicated that most of these compounds are metastable. A combination of X-ray powder diffraction and differential thermal analysis were used to determine various low temperature decomposition pathways; these pathways were very dependent on the interlayer species. Overall the ANdNb{sub 2}O{sub 7} series was found to be less stable than the corresponding lanthanides, ALaNb{sub 2}O{sub 7}. - Graphical abstract: Amore » new series of topochemically-prepared metastable neodymium-containing layered perovskites are studied. - Highlights: • A series of new layered neodymium containing perovskites were synthesized by ion exchange. • Products were studied by variable temperature X-ray diffraction and thermal analysis. • Most of the series are metastable showing exothermic transitions on decomposition. • The Nd compounds are less stable due to the smaller size of the Nd relative to La.« less
  • High voltage cathode materials Li-excess layered oxide compounds Li[Ni{sub x}Li{sub 1/3-2x/3}Mn{sub 2/3-x/3}]O{sub 2} (0 < x < 1/2) are investigated in a joint study combining both computational and experimental methods. The bulk and surface structures of pristine and cycled samples of Li[Ni{sub 1/5}Li{sub 1/5}Mn{sub 3/5}]O{sub 2} are characterized by synchrotron X-Ray diffraction together with aberration corrected Scanning Transmission Electron Microscopy (a-S/TEM). Electron Energy Loss Spectroscopy (EELS) is carried out to investigate the surface changes of the samples before/after electrochemical cycling. Combining first principles computational investigation with our experimental observations, a detailed lithium de-intercalation mechanism is proposed for this family ofmore » Li-excess layered oxides. The most striking characteristics in these high voltage high energy density cathode materials are (1) formation of tetrahedral lithium ions at voltage less than 4.45 V and (2) the transition metal (TM) ions migration leading to phase transformation on the surface of the materials. We show clear evidence of a new spinel-like solid phase formed on the surface of the electrode materials after high-voltage cycling. It is proposed that such surface phase transformation is one of the factors contributing to the first cycle irreversible capacity and the main reason for the intrinsic poor rate capability of these materials.« less