Berlin 2008 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 45: Nanostructured Materials VI
MM 45.4: Vortrag
Donnerstag, 28. Februar 2008, 15:45–16:00, H 0111
Li diffusion in nanocrystalline and nanoglassy β-spodumene LiAlSi2O6 — •Alexander Kuhn, Martin Wilkening, and Paul Heitjans — Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3-3a, 30167 Hannover
Recently nanocrystalline and nanoglassy ceramics have been a subject of growing research interest. In the present study β-spodumene LiAlSi2O6 and the corresponding glass were used as a model system. The influence of particle size on Li ion dynamics was studied by 7Li NMR spin-lattice relaxation rate measurements. As a general trend, the Li diffusivity in the glassy sample is larger than that in the µm-sized crystalline material [1, 2]. However, as the particle size decreases, the nanocrystalline material shows enhanced diffusivity whilst the opposite effect is found for the nanoglassy ceramics. The nanocrystalline and nanoglassy samples were prepared by high-energy ball-milling of the coarse grained starting material and the corresponding glass, respectively. A possible structural model trying to explain the observed convergence of the diffusivities of the nanocrystalline and nanoglassy samples is discussed.
[1] F. Qi, C. Rier, R. Böhmer, W. Franke and P. Heitjans, Phys. Rev. B 72 (2005) 10430.
[2] W. Franke and P. Heitjans, Ber. Bunsenges. Phys. Chem. 96 (1992) 1674.