Preparation and characterization of Cd_0.75PS₃A_0.5(H₂O)_y [A=Na, K and Cs]

Abstract

Cd_0.75PS₃A_0.5(H₂O)_y [A=Na, K and Cs], synthesized by the ion-exchange intercalation reaction of the insulating layered CdPS₃, exhibits interesting electrical properties. The electrical properties are strongly dependent on the extent of hydration of the alkali ion which resides in the interlamellar space. In the potassium and caesium ion-exchanged compounds, y=1, the lattice expansion is ~3 Å and the electric response characteristic of a dielectric. In the as prepared A=Na compound, y=2, the lattice expansion is 5.6 Å, the compound is conducting with a DC conductance of 3×10⁻⁵ S cm⁻¹ at 300 K. Cd_0.75PS₃Na_0.5(H₂O)_y, y=2, on evacuation or on heating looses water, reversibly, to form a y=1 phase with electrical properties similar to that of the K and Cs ion exchange intercalation compounds.