Single crystals of TiS2(0001) were intercalated sequentially by Li and Na. The intercalation occurred across the Van der Waals planes, by deposition onto the basal plane of TiS2. The investigation took place in UHV by soft X-ray photoelectron spectroscopy. Deposition of Na onto Li-intercalated TiS2(0001) caused the Li to move further into the bulk of the substrate. However, deposition of Li onto Na-intercalated TiS2(0001) forced Na to move out towards the surface by an exchange mechanism. These interactions between intercalated Li and Na into TiS2(0001) and their subsequent behaviour have been explained by a correlation of thermodynamic (Gibbs free energy), kinetic (diffusion coefficient) and electrostatic effects.

Surf. Sci.

Papageorgopoulos, C. A., Kamaratos, M., Papageorgopoulos, D. C., Tonti, D., Pettenkofer, C., & Jaegermann, W. (1999). Exchange reaction between Li and Na intercalated into TiS2. Surf. Sci., 436, 213–219.