Crystal Structure and Local Dynamics in Tetrahedral Proton-Conducting La1-xBa1+xGaO4

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11 Citazioni (Scopus)

Abstract

La1-xBa1+xGaO4-0 (LBG) compounds, based on unconnected GaO4 moieties, were recently proposed as proton conductors. Protonic defects in the lattice are inserted through self-doping with Ba2+, to create oxygen vacancies subsequently filled by hydroxyl ions. We present a combined structural analysis on self-doped LBG using X-ray diffraction (XRD) and X-ray absorption (EXAFS): these results unravel the finer structural details on the short-range and long-range scales, and they are correlated with the dynamical properties of protonic conduction coming from vibrational spectroscopy. The structure of the GaO4 groups is independent of the oxide composition. On hydration, an array of short intertetrahedral hydrogen bonds is formed, producing a contraction of the a axis. On the basis of thermogravimetric analysis, EXAFS, XRD and infrared spectroscopy (IR) results, we propose that the stiffness of the GaO4 tetrahedra hinders the intratetrahedral proton transfer, while the noticeable fraction of protons involved in strong hydrogen bonds limit the proton reorientational freedom.
Lingua originaleEnglish
pagine (da-a)298-304
Numero di pagine7
RivistaJOURNAL OF PHYSICAL CHEMISTRY. C
Volume115
Stato di pubblicazionePublished - 2011

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Protons
Crystal structure
conduction
crystal structure
protons
Hydrogen bonds
X ray diffraction
Vibrational spectroscopy
Proton transfer
X ray absorption
Oxygen vacancies
spectroscopy
hydrogen bonds
Structural analysis
Hydration
Oxides
x rays
Thermogravimetric analysis
Infrared spectroscopy
Doping (additives)

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry
  • Energy(all)

Cita questo

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title = "Crystal Structure and Local Dynamics in Tetrahedral Proton-Conducting La1-xBa1+xGaO4",
abstract = "La1-xBa1+xGaO4-0 (LBG) compounds, based on unconnected GaO4 moieties, were recently proposed as proton conductors. Protonic defects in the lattice are inserted through self-doping with Ba2+, to create oxygen vacancies subsequently filled by hydroxyl ions. We present a combined structural analysis on self-doped LBG using X-ray diffraction (XRD) and X-ray absorption (EXAFS): these results unravel the finer structural details on the short-range and long-range scales, and they are correlated with the dynamical properties of protonic conduction coming from vibrational spectroscopy. The structure of the GaO4 groups is independent of the oxide composition. On hydration, an array of short intertetrahedral hydrogen bonds is formed, producing a contraction of the a axis. On the basis of thermogravimetric analysis, EXAFS, XRD and infrared spectroscopy (IR) results, we propose that the stiffness of the GaO4 tetrahedra hinders the intratetrahedral proton transfer, while the noticeable fraction of protons involved in strong hydrogen bonds limit the proton reorientational freedom.",
author = "Antonino Martorana and Francesco Giannici and Alessandro Longo",
year = "2011",
language = "English",
volume = "115",
pages = "298--304",
journal = "Journal of Physical Chemistry C",
issn = "1932-7447",
publisher = "American Chemical Society",

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TY - JOUR

T1 - Crystal Structure and Local Dynamics in Tetrahedral Proton-Conducting La1-xBa1+xGaO4

AU - Martorana, Antonino

AU - Giannici, Francesco

AU - Longo, Alessandro

PY - 2011

Y1 - 2011

N2 - La1-xBa1+xGaO4-0 (LBG) compounds, based on unconnected GaO4 moieties, were recently proposed as proton conductors. Protonic defects in the lattice are inserted through self-doping with Ba2+, to create oxygen vacancies subsequently filled by hydroxyl ions. We present a combined structural analysis on self-doped LBG using X-ray diffraction (XRD) and X-ray absorption (EXAFS): these results unravel the finer structural details on the short-range and long-range scales, and they are correlated with the dynamical properties of protonic conduction coming from vibrational spectroscopy. The structure of the GaO4 groups is independent of the oxide composition. On hydration, an array of short intertetrahedral hydrogen bonds is formed, producing a contraction of the a axis. On the basis of thermogravimetric analysis, EXAFS, XRD and infrared spectroscopy (IR) results, we propose that the stiffness of the GaO4 tetrahedra hinders the intratetrahedral proton transfer, while the noticeable fraction of protons involved in strong hydrogen bonds limit the proton reorientational freedom.

AB - La1-xBa1+xGaO4-0 (LBG) compounds, based on unconnected GaO4 moieties, were recently proposed as proton conductors. Protonic defects in the lattice are inserted through self-doping with Ba2+, to create oxygen vacancies subsequently filled by hydroxyl ions. We present a combined structural analysis on self-doped LBG using X-ray diffraction (XRD) and X-ray absorption (EXAFS): these results unravel the finer structural details on the short-range and long-range scales, and they are correlated with the dynamical properties of protonic conduction coming from vibrational spectroscopy. The structure of the GaO4 groups is independent of the oxide composition. On hydration, an array of short intertetrahedral hydrogen bonds is formed, producing a contraction of the a axis. On the basis of thermogravimetric analysis, EXAFS, XRD and infrared spectroscopy (IR) results, we propose that the stiffness of the GaO4 tetrahedra hinders the intratetrahedral proton transfer, while the noticeable fraction of protons involved in strong hydrogen bonds limit the proton reorientational freedom.

UR - http://hdl.handle.net/10447/54751

M3 - Article

VL - 115

SP - 298

EP - 304

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

ER -