Details
| Original language | English |
|---|---|
| Pages (from-to) | 19-24 |
| Number of pages | 6 |
| Journal | Journal of non-crystalline solids |
| Volume | 293-295 |
| Issue number | 1 |
| Publication status | Published - Nov 2001 |
Abstract
7Li NMR spectra of ball-milled nanocrystalline LixTiS2 have been recorded in the temperature range 140 ≤ T ≤ 500 K. Above 250 K, the central transition of the spectra decomposes into a broad and a narrow component at the same centre frequency. The relative intensity of the narrow line increases with temperature, finally reaching a saturation value of 50%. The narrow line is attributed to more mobile spins in the interfacial regions between the nanocrystalline grains. The temperature dependent intensity of the narrow component is interpreted in terms of an inhomogeneous interface structure. The average particle size of nanocrystalline LixTiS2 as obtained from X-ray diffraction (XRD) is 11.8 nm. A simple geometrical model involving the particle diameter d (from XRD), the interface fraction f (from NMR), and the interface thickness g predicts unreasonably thick interfaces but is in accordance with the measured data for d and f when it is adapted to account for a disk-like particle shape. On the basis of the disk model, which is likely to apply for a layered structure like LixTiS2, the interface thickness is limited by 1 ≤ g ≤ 3 nm. The results are compared to those obtained for some three-dimensional structures, to which the standard spherical model is applicable in most cases.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Physics and Astronomy(all)
- Condensed Matter Physics
- Materials Science(all)
- Materials Chemistry
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In: Journal of non-crystalline solids, Vol. 293-295, No. 1, 11.2001, p. 19-24.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Intergranular structure of nanocrystalline layered LixTiS2 as derived from 7Li NMR spectroscopy
AU - Winter, Rudolf
AU - Heitjans, Paul
N1 - Funding Information: We would like to thank Dr Roderich Röttger for assistance with the X-ray diffractometer and Zentralabteilung Chemische Analysen, Forschungszentrum Jülich, for the chemical analysis. Part of this work was funded by the Deutsche Forschungsgemeinschaft. Paul Heitjans would also like to acknowledge financial help by the Fonds der Chemischen Industrie.
PY - 2001/11
Y1 - 2001/11
N2 - 7Li NMR spectra of ball-milled nanocrystalline LixTiS2 have been recorded in the temperature range 140 ≤ T ≤ 500 K. Above 250 K, the central transition of the spectra decomposes into a broad and a narrow component at the same centre frequency. The relative intensity of the narrow line increases with temperature, finally reaching a saturation value of 50%. The narrow line is attributed to more mobile spins in the interfacial regions between the nanocrystalline grains. The temperature dependent intensity of the narrow component is interpreted in terms of an inhomogeneous interface structure. The average particle size of nanocrystalline LixTiS2 as obtained from X-ray diffraction (XRD) is 11.8 nm. A simple geometrical model involving the particle diameter d (from XRD), the interface fraction f (from NMR), and the interface thickness g predicts unreasonably thick interfaces but is in accordance with the measured data for d and f when it is adapted to account for a disk-like particle shape. On the basis of the disk model, which is likely to apply for a layered structure like LixTiS2, the interface thickness is limited by 1 ≤ g ≤ 3 nm. The results are compared to those obtained for some three-dimensional structures, to which the standard spherical model is applicable in most cases.
AB - 7Li NMR spectra of ball-milled nanocrystalline LixTiS2 have been recorded in the temperature range 140 ≤ T ≤ 500 K. Above 250 K, the central transition of the spectra decomposes into a broad and a narrow component at the same centre frequency. The relative intensity of the narrow line increases with temperature, finally reaching a saturation value of 50%. The narrow line is attributed to more mobile spins in the interfacial regions between the nanocrystalline grains. The temperature dependent intensity of the narrow component is interpreted in terms of an inhomogeneous interface structure. The average particle size of nanocrystalline LixTiS2 as obtained from X-ray diffraction (XRD) is 11.8 nm. A simple geometrical model involving the particle diameter d (from XRD), the interface fraction f (from NMR), and the interface thickness g predicts unreasonably thick interfaces but is in accordance with the measured data for d and f when it is adapted to account for a disk-like particle shape. On the basis of the disk model, which is likely to apply for a layered structure like LixTiS2, the interface thickness is limited by 1 ≤ g ≤ 3 nm. The results are compared to those obtained for some three-dimensional structures, to which the standard spherical model is applicable in most cases.
UR - http://www.scopus.com/inward/record.url?scp=0035501053&partnerID=8YFLogxK
U2 - 10.1016/S0022-3093(01)00640-8
DO - 10.1016/S0022-3093(01)00640-8
M3 - Article
AN - SCOPUS:0035501053
VL - 293-295
SP - 19
EP - 24
JO - Journal of non-crystalline solids
JF - Journal of non-crystalline solids
SN - 0022-3093
IS - 1
ER -