Ultraslow Cation Diffusion in Li Intercalated Cubic TiS2

1. Introduction The Li intercalated polymorphs of titanium disulfide – the trigonal (layered) and the cubic modification – form a unique model system for comparison of Li self-diffusion in two and three dimensions, respectively, within two host structures of the same composition [1]. Slow Li + transport in cubic Li x TiS 2 (x = 0.6) was probed by 7 Li stimulated echo NMR spectroscopy (see, e. g., [2,3]) and compared with results obtained by recording diffusion induced maxima of the NMR spin-lattice relaxation rate 1/T 1ρ in the rotating frame. Both methods are sensitive to very slow Li jumps. Whereas 1/T 1ρ-measurements are useful to detect Li jumps with rates between 10 4 to 10 5 s –1 , ultraslow Li motions down to the sub-Hz range are directly accessible by the stimulated echo NMR technique. Furthermore , the data is compared with results on Li diffusion in the layered, trigonal modification Li 0.7 TiS 2 [4].