Subproject 1: Low-dimensional lithium ion conductors
|Supervisor:||Heitjans, Wilkening, Lerch|
NMR techniques will be employed which are sensitive to both the mobility of the Li ions and the dimensionality of the diffusion process. One and two dimensional diffusion can be distinguished by means of temperature dependent and frequency dependent 6,7Li NMR spin-lattice relaxation (SLR) measurements. Both 1D and 2D lithium-ion conductors show a characteristic asymmetry of the diffusion-induced SLR NMR rate peak. Furthermore, the rates reveal a characteristic dependence on the Larmor frequency. Besides NMR techniques, for which polycrystalline materials are sufficient, macroscopic methods can be employed in the case of single crystalline samples. Here, the dimensionality of the transport process is reflected by the anisotropy of the mass or charge transport. Macroscopic techniques include impedance spectroscopy, mass tracer measurements and field gradient NMR spectroscopy.
Fig.: Arrhenius plots of the 7Li NMR SLR rates in the laboratory frame and those in the rotating frame. (Reprinted with permission from . Copyright 2011 American Chemical Society.)
Employees: Dipl.-Phys. K. Volgmann, Dr. V. Epp, Dr. S. Nakhal.
 V. Epp and M. Wilkening, Phys. Rev. B 82 (2010) 020301.
 A. Kuhn, P. Sreeraj, R. Pöttgen, H.-D. Wiemhöfer, M. Wilkening, and P. Heitjans, J. Am. Soc. 113 (2011) 11018.
 A. Kuhn, P. Sreeraj, R. Pöttgen, H.-D. Wiemhöfer, M. Wilkening, and P. Heitjans, Angew. Chem. Intern. Ed. 50 (2011) 12099.
 A. Kuhn, M. Kunze, P. Sreeraj, H.-D. Wiemhöfer, V. Thangadurai, M. Wilkening, and P. Heitjans, Solid State Nucl. Magn. Reson. 42 (2012) 2.