Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 17: Poster Session
MM 17.56: Poster
Montag, 26. März 2012, 17:00–19:00, Poster B
Lithium ion dynamics in channel-structured Li2Ti6O13 — •Kai Volgmann and Paul Heitjans — Leibniz Universität Hannover, Inst. f. Phys. Chemie u. Elektrochemie, Callinstraße 3 - 3a, D-30167 Hannover
Solid-state nuclear magnetic resonance (NMR) spectroscopy subsumes a couple of powerful techniques to investigate the diffusion of Li ions on the microscopic scale. These methods can be used, e. g., to investigate effects on the motion of Li+ ions by dimensionality reduction. In this work, Li2Ti6O13 (space group C m/2) has been chosen as model system due to its channel-like crystal structure. Lithium is supposed to be solely located inside the channels. Samples with varying Li content have been studied. Synthesis is done via a solid-state reaction and subsequent ion exchange of sodium ions. The samples were characterized by powder x-ray diffraction and inductively coupled plasma optical emission spectroscopy. 7Li NMR relaxometry measurements have been performed at different Lamor frequencies ω0. Due to the channel-like structure, a confined Li diffusion process is expected leading to a frequency-dependent spin-lattice relaxation rate in the regime ω0· τ≪1 where τ is the motional correlation time. A blocking effect in the structure due to the sodium cations is observed for samples with substoichiometric Li concentration.