Details
| Original language | English |
|---|---|
| Pages (from-to) | 67-82 |
| Number of pages | 16 |
| Journal | Faraday discussions |
| Volume | 134 |
| Publication status | Published - 2007 |
Abstract
Lithium niobate has been chosen as a model system for spectroscopic studies of the influence of different structural forms and preparation routes of an ionic conductor on its ion transport properties. The Li diffusivity in nanocrystalline LiNbO3, prepared either mechanically by high energy ball milling or chemically by a sol-gel route, was studied by means of impedance and solid state 7Li NMR spectroscopy. The Li diffusivity turned out to be strongly correlated with the different grain boundary microstructures of the two nanocrystalline samples and with the degree of disorder introduced during preparation, as seen especially by HRTEM and EXAFS. Although in both samples nanostructuring yields an enhancement of the Li diffusivity compared to that in coarse grained LiNbO3, the Li diffusivity in ball milled LiNbO3 is much higher than in chemically prepared nanocrystalline LiNbO3. The former LiNbO3 sample has a large volume fraction of highly disordered interfacial regions which seem to be responsible for fast Li diffusion and to have a structure very similar to that of the amorphous form. This is in contrast to the chemically prepared sample where these regions have a smaller volume fraction.
ASJC Scopus subject areas
- Chemistry(all)
- Physical and Theoretical Chemistry
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In: Faraday discussions, Vol. 134, 2007, p. 67-82.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - NMR and impedance studies of nanocrystalline and amorphous ion conductors
T2 - Lithium niobate as a model system
AU - Heitjans, Paul
AU - Masoud, Muayad
AU - Feldhoff, Armin
AU - Wilkening, Martin
PY - 2007
Y1 - 2007
N2 - Lithium niobate has been chosen as a model system for spectroscopic studies of the influence of different structural forms and preparation routes of an ionic conductor on its ion transport properties. The Li diffusivity in nanocrystalline LiNbO3, prepared either mechanically by high energy ball milling or chemically by a sol-gel route, was studied by means of impedance and solid state 7Li NMR spectroscopy. The Li diffusivity turned out to be strongly correlated with the different grain boundary microstructures of the two nanocrystalline samples and with the degree of disorder introduced during preparation, as seen especially by HRTEM and EXAFS. Although in both samples nanostructuring yields an enhancement of the Li diffusivity compared to that in coarse grained LiNbO3, the Li diffusivity in ball milled LiNbO3 is much higher than in chemically prepared nanocrystalline LiNbO3. The former LiNbO3 sample has a large volume fraction of highly disordered interfacial regions which seem to be responsible for fast Li diffusion and to have a structure very similar to that of the amorphous form. This is in contrast to the chemically prepared sample where these regions have a smaller volume fraction.
AB - Lithium niobate has been chosen as a model system for spectroscopic studies of the influence of different structural forms and preparation routes of an ionic conductor on its ion transport properties. The Li diffusivity in nanocrystalline LiNbO3, prepared either mechanically by high energy ball milling or chemically by a sol-gel route, was studied by means of impedance and solid state 7Li NMR spectroscopy. The Li diffusivity turned out to be strongly correlated with the different grain boundary microstructures of the two nanocrystalline samples and with the degree of disorder introduced during preparation, as seen especially by HRTEM and EXAFS. Although in both samples nanostructuring yields an enhancement of the Li diffusivity compared to that in coarse grained LiNbO3, the Li diffusivity in ball milled LiNbO3 is much higher than in chemically prepared nanocrystalline LiNbO3. The former LiNbO3 sample has a large volume fraction of highly disordered interfacial regions which seem to be responsible for fast Li diffusion and to have a structure very similar to that of the amorphous form. This is in contrast to the chemically prepared sample where these regions have a smaller volume fraction.
UR - http://www.scopus.com/inward/record.url?scp=33845504663&partnerID=8YFLogxK
U2 - 10.1039/b602887j
DO - 10.1039/b602887j
M3 - Article
AN - SCOPUS:33845504663
VL - 134
SP - 67
EP - 82
JO - Faraday discussions
JF - Faraday discussions
SN - 1359-6640
ER -