Details
| Original language | English |
|---|---|
| Pages (from-to) | 5091-5096 |
| Number of pages | 6 |
| Journal | Journal of materials science |
| Volume | 39 |
| Issue number | 16-17 |
| Publication status | Published - Aug 2004 |
Abstract
Nanocrystalline materials can show enhanced diffusivity compared to their microcrystalline counterparts due to the large fraction of atoms or ions located in interfacial regions. In the case of ceramics, resulting properties with potential applications are, e.g., fast ionic conductivity, high mechanical creep rate and increased catalytic activity. Different nanocrystalline ceramic materials were prepared by high-energy ball milling of coarse grained source materials. The samples were characterized by XRD, TEM, BET method and IR spectroscopy. These measurements show that the primary crystallites form larger agglomerates with internal interfaces and that the reduction of the crystallite size is accompanied by a structural degradation of the surface zone. An example is the partial amorphization observed for LiBO2 by IR spectroscopy. The diffusivity and ion conductivity in these materials was studied by NMR relaxation, NMR line shape and impedance spectroscopies. It was possible to discriminate between highly mobile ions in the interfacial regions and immobile ions in the grains. In general diffusion in the nanocrystalline systems was found to be fast compared to that in the corresponding microcrystalline source materials.
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Engineering(all)
- Mechanics of Materials
- Engineering(all)
- Mechanical Engineering
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In: Journal of materials science, Vol. 39, No. 16-17, 08.2004, p. 5091-5096.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Fast diffusion in nanocrystalline ceramics prepared by ball milling
AU - Heitjans, Paul
AU - Indris, Sylvio
N1 - Funding Information: We are grateful to the Deutsche Forschungsgemein-schaft for financial support. We thank Dr. Christian Kübel (FEI Company, Eindhoven) for TEM micrographs.
PY - 2004/8
Y1 - 2004/8
N2 - Nanocrystalline materials can show enhanced diffusivity compared to their microcrystalline counterparts due to the large fraction of atoms or ions located in interfacial regions. In the case of ceramics, resulting properties with potential applications are, e.g., fast ionic conductivity, high mechanical creep rate and increased catalytic activity. Different nanocrystalline ceramic materials were prepared by high-energy ball milling of coarse grained source materials. The samples were characterized by XRD, TEM, BET method and IR spectroscopy. These measurements show that the primary crystallites form larger agglomerates with internal interfaces and that the reduction of the crystallite size is accompanied by a structural degradation of the surface zone. An example is the partial amorphization observed for LiBO2 by IR spectroscopy. The diffusivity and ion conductivity in these materials was studied by NMR relaxation, NMR line shape and impedance spectroscopies. It was possible to discriminate between highly mobile ions in the interfacial regions and immobile ions in the grains. In general diffusion in the nanocrystalline systems was found to be fast compared to that in the corresponding microcrystalline source materials.
AB - Nanocrystalline materials can show enhanced diffusivity compared to their microcrystalline counterparts due to the large fraction of atoms or ions located in interfacial regions. In the case of ceramics, resulting properties with potential applications are, e.g., fast ionic conductivity, high mechanical creep rate and increased catalytic activity. Different nanocrystalline ceramic materials were prepared by high-energy ball milling of coarse grained source materials. The samples were characterized by XRD, TEM, BET method and IR spectroscopy. These measurements show that the primary crystallites form larger agglomerates with internal interfaces and that the reduction of the crystallite size is accompanied by a structural degradation of the surface zone. An example is the partial amorphization observed for LiBO2 by IR spectroscopy. The diffusivity and ion conductivity in these materials was studied by NMR relaxation, NMR line shape and impedance spectroscopies. It was possible to discriminate between highly mobile ions in the interfacial regions and immobile ions in the grains. In general diffusion in the nanocrystalline systems was found to be fast compared to that in the corresponding microcrystalline source materials.
UR - http://www.scopus.com/inward/record.url?scp=4444335464&partnerID=8YFLogxK
U2 - 10.1023/B:JMSC.0000039189.17243.72
DO - 10.1023/B:JMSC.0000039189.17243.72
M3 - Article
AN - SCOPUS:4444335464
VL - 39
SP - 5091
EP - 5096
JO - Journal of materials science
JF - Journal of materials science
SN - 0022-2461
IS - 16-17
ER -