Diffusion parameters in single-crystalline Li(3)N as probed by (6)Li and (7)Li spin-alignment echo NMR spectroscopy in comparison with results from (8)Li beta-radiation detected NMR
نویسندگان
چکیده
6Li and 7Li two-time spin-alignment echo NMR correlation functions of single-crystalline LbN are recorded. Around room temperature, the decay of the spin-alignment echo amplitudes is induced by slow Li jumps perpendicular to the LbN layers. The hopping correlation functions can be best represented by a single exponential. The measured jump rates are consistent with those which were previously determined by 8Li fi-radiation detected NMR at much lower temperatures. Taking the results from 6Li and 7Li NMR as well as from 8Li fi-NMR together, between 360 and 220 K Arrhenius behaviour is found. The corresponding activation energy is 0.65(1) eV and the pre-exponential factor turned out to be 6.4(5) x 1013 S-I. Although probed from a microscopic point of view, the NMR diffusion parameters are in very good agreement with those obtained from dc-conductivity measurements, being sensitive to macroscopic transport properties.
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