Variation of the preexponential factor and activation energy for lithium diffusion in cubic titanium disulfide

The chemical, D, and self diffusion, D, coefficients for lithium transport within the cubic polymorph of TiS₂ have been determined as a function of temperature and composition by ac impedance measurements. Both D and D vary with the lithium content, reaching maxima at 23°C of 5.6 × 10^-10 and 6.9 × 10^-9 cm²sec^-1, respectively. The Arrhenius plots for the self diffusion coefficient are linear; however, the preexponential factor and activation energy vary significantly with composition displaying a broad minimum centered at x = 0.5. This behavior is associated with interactions between the mobile ions; two possible models for ion interactions are presented, either or both of which may be important in these systems. © 1990.