Synthesis and characterization of two crystallographic forms of Ag0.79VS2.

A previously unreported compound, Ag0.79VS2, has been synthesized; its structure and elementary properties are reported. Ag0.79VS2 crystallizes in two forms, designated as the α and β, related to the 1s-InTaS2 structure. Single crystal x-ray diffraction shows the α form to have a single layer hexagonal structure with a unit cell of 3.213(3)Å×7.809(6)Å, consisting of layers of edge-shared VS6 triangular prisms separated by layers of Ag. The β form is similar but has an supercell in the basal plane, yielding a unit cell of 5.573(5)Å×7.822(6)Å. Both forms have disordered and displaced silver in the basal plane, but the β form has partial ordering of its silver sublattice and in-plane vanadium trimers. Resistivity measurements show metallic temperature dependence with an unusual hysteresis between 210K and 130K. Magnetic susceptibility measurements show Pauli Paramagnetic behavior. The Seebeck coefficient at 300K is 42µV/K. [ABSTRACT FROM AUTHOR]