Intercalation compounds of metal hydroxides with group V layered dichalcogenides

Abstract

The layered dichalcogenides of Nb and Ta easily form intercalation compounds with metal hydroxides (alkali, alkaline earth, ammonium hydroxide, and their derivatives) in aqueous solution. The increase per unit layer in the c lattice parameter produced upon intercalation varies from 2 to 6 Å and is dependent on the host dichalcogenide, the metal hydroxide employed, and its solvation number. A formula of the type TaS2(MOH)0.2-0.3(H20)0.5-0.8 was obtained from chemical analyses data. The formation of different intercalation stages, structural aspects, and superconductivity of these compounds are described and discussed.