Details
| Original language | English |
|---|---|
| Article number | 007 |
| Pages (from-to) | 9849-9862 |
| Number of pages | 14 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 18 |
| Issue number | 43 |
| Publication status | Published - 1 Nov 2006 |
Abstract
Lithium self-diffusion in the low-temperature modification of polycrystalline lithium ortho-silicate Li4SiO4 is investigated by 7Li two-time stimulated echo NMR spectroscopy. Extremely slow Li exchange processes were directly monitored between 300 and 433K by recording spin-alignment echoes as a function of mixing time varying over six decades from 10-5 to 10s. In the investigated temperature range the hopping correlation functions show biexponential behaviour. Whereas the first decay step reflects directly Li jumps between electrically different sites, the second one is simply induced by the decay of alignment order due to quadrupolar relaxation. The echo decay rates τ-1(10 1s-1≤τ-1≤104s -1), which can be identified with Li jump rates, show Arrhenius behaviour with an activation energy of 0.53(1)eV. The directly measured jump rates are in good agreement with those obtained recently by one-and two-dimensional 6Li exchange MAS NMR reported in the literature.
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Journal of Physics Condensed Matter, Vol. 18, No. 43, 007, 01.11.2006, p. 9849-9862.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Extremely slow cation exchange processes in Li4SiO4 probed directly by two-time 7Li stimulated-echo nuclear magnetic resonance spectroscopy
AU - Wilkening, Martin
AU - Heitjans, Paul
PY - 2006/11/1
Y1 - 2006/11/1
N2 - Lithium self-diffusion in the low-temperature modification of polycrystalline lithium ortho-silicate Li4SiO4 is investigated by 7Li two-time stimulated echo NMR spectroscopy. Extremely slow Li exchange processes were directly monitored between 300 and 433K by recording spin-alignment echoes as a function of mixing time varying over six decades from 10-5 to 10s. In the investigated temperature range the hopping correlation functions show biexponential behaviour. Whereas the first decay step reflects directly Li jumps between electrically different sites, the second one is simply induced by the decay of alignment order due to quadrupolar relaxation. The echo decay rates τ-1(10 1s-1≤τ-1≤104s -1), which can be identified with Li jump rates, show Arrhenius behaviour with an activation energy of 0.53(1)eV. The directly measured jump rates are in good agreement with those obtained recently by one-and two-dimensional 6Li exchange MAS NMR reported in the literature.
AB - Lithium self-diffusion in the low-temperature modification of polycrystalline lithium ortho-silicate Li4SiO4 is investigated by 7Li two-time stimulated echo NMR spectroscopy. Extremely slow Li exchange processes were directly monitored between 300 and 433K by recording spin-alignment echoes as a function of mixing time varying over six decades from 10-5 to 10s. In the investigated temperature range the hopping correlation functions show biexponential behaviour. Whereas the first decay step reflects directly Li jumps between electrically different sites, the second one is simply induced by the decay of alignment order due to quadrupolar relaxation. The echo decay rates τ-1(10 1s-1≤τ-1≤104s -1), which can be identified with Li jump rates, show Arrhenius behaviour with an activation energy of 0.53(1)eV. The directly measured jump rates are in good agreement with those obtained recently by one-and two-dimensional 6Li exchange MAS NMR reported in the literature.
UR - http://www.scopus.com/inward/record.url?scp=33846095934&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/18/43/007
DO - 10.1088/0953-8984/18/43/007
M3 - Article
AN - SCOPUS:33846095934
VL - 18
SP - 9849
EP - 9862
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 43
M1 - 007
ER -