Details
| Originalsprache | Englisch |
|---|---|
| Aufsatznummer | 024311 |
| Fachzeitschrift | Physical Review B - Condensed Matter and Materials Physics |
| Jahrgang | 77 |
| Ausgabenummer | 2 |
| Publikationsstatus | Veröffentlicht - 31 Jan. 2008 |
Abstract
Li7 spin-alignment NMR is used to trace ultraslow diffusion of Li+ in the layered Li conductor Lix Ti S2 (x=0.7). Two-time correlation functions were recorded for fixed evolution times as a function of mixing time at temperatures within the Li7 rigid-lattice regime. The corresponding decay rates were identified as Li jump rates τ-1 ranging from 10-1 to 103 s-1 between temperatures T=148 K and 213 K. The jump rates obtained directly from spin-alignment echo NMR and those from diffusion induced maxima of spin-lattice relaxation peaks, monitored in the laboratory as well as in the rotating frame, are consistent with each other and follow an Arrhenius law with an activation energy of 0.41 (1) eV and a preexponential factor of 6.3 (1) × 1012 s-1. Altogether, a solitary Li diffusion process was found between 148 and 510 K. Li diffusion was investigated in a dynamic range of about 10 orders of magnitude, i.e., 0.1≤ τ-1 ≤7.8× 108 s-1. Additionally, the analysis of final-state echo amplitudes of the two-time correlation functions revealed information about the Li diffusion pathway in Li0.7 Ti S2. Obviously, a two-site jump process is present, i.e., besides the regularly occupied octahedral sites also the vacant tetrahedral ones within the van der Waals gap are involved in the overall two-dimensional diffusion process.
ASJC Scopus Sachgebiete
- Werkstoffwissenschaften (insg.)
- Elektronische, optische und magnetische Materialien
- Physik und Astronomie (insg.)
- Physik der kondensierten Materie
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in: Physical Review B - Condensed Matter and Materials Physics, Jahrgang 77, Nr. 2, 024311, 31.01.2008.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Li jump process in h- Li0.7 Ti S2 studied by two-time Li7 spin-alignment echo NMR and comparison with results on two-dimensional diffusion from nuclear magnetic relaxation
AU - Wilkening, M.
AU - Heitjans, P.
PY - 2008/1/31
Y1 - 2008/1/31
N2 - Li7 spin-alignment NMR is used to trace ultraslow diffusion of Li+ in the layered Li conductor Lix Ti S2 (x=0.7). Two-time correlation functions were recorded for fixed evolution times as a function of mixing time at temperatures within the Li7 rigid-lattice regime. The corresponding decay rates were identified as Li jump rates τ-1 ranging from 10-1 to 103 s-1 between temperatures T=148 K and 213 K. The jump rates obtained directly from spin-alignment echo NMR and those from diffusion induced maxima of spin-lattice relaxation peaks, monitored in the laboratory as well as in the rotating frame, are consistent with each other and follow an Arrhenius law with an activation energy of 0.41 (1) eV and a preexponential factor of 6.3 (1) × 1012 s-1. Altogether, a solitary Li diffusion process was found between 148 and 510 K. Li diffusion was investigated in a dynamic range of about 10 orders of magnitude, i.e., 0.1≤ τ-1 ≤7.8× 108 s-1. Additionally, the analysis of final-state echo amplitudes of the two-time correlation functions revealed information about the Li diffusion pathway in Li0.7 Ti S2. Obviously, a two-site jump process is present, i.e., besides the regularly occupied octahedral sites also the vacant tetrahedral ones within the van der Waals gap are involved in the overall two-dimensional diffusion process.
AB - Li7 spin-alignment NMR is used to trace ultraslow diffusion of Li+ in the layered Li conductor Lix Ti S2 (x=0.7). Two-time correlation functions were recorded for fixed evolution times as a function of mixing time at temperatures within the Li7 rigid-lattice regime. The corresponding decay rates were identified as Li jump rates τ-1 ranging from 10-1 to 103 s-1 between temperatures T=148 K and 213 K. The jump rates obtained directly from spin-alignment echo NMR and those from diffusion induced maxima of spin-lattice relaxation peaks, monitored in the laboratory as well as in the rotating frame, are consistent with each other and follow an Arrhenius law with an activation energy of 0.41 (1) eV and a preexponential factor of 6.3 (1) × 1012 s-1. Altogether, a solitary Li diffusion process was found between 148 and 510 K. Li diffusion was investigated in a dynamic range of about 10 orders of magnitude, i.e., 0.1≤ τ-1 ≤7.8× 108 s-1. Additionally, the analysis of final-state echo amplitudes of the two-time correlation functions revealed information about the Li diffusion pathway in Li0.7 Ti S2. Obviously, a two-site jump process is present, i.e., besides the regularly occupied octahedral sites also the vacant tetrahedral ones within the van der Waals gap are involved in the overall two-dimensional diffusion process.
UR - http://www.scopus.com/inward/record.url?scp=38849121245&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.77.024311
DO - 10.1103/PhysRevB.77.024311
M3 - Article
AN - SCOPUS:38849121245
VL - 77
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 1098-0121
IS - 2
M1 - 024311
ER -