Synthesis of a Family of {[(VSe₂)_n]_1.06(TaSe₂)_m}_z Compounds

Abstract

The first sixteen members of the {[(VSe2)n]1.06(TaSe2)m}z family of compounds where n and m were varied from 1 to 4 were synthesized by annealing preconfigured reactants. The factor of 1.06 originates from the ab-plane lattice mismatch of VSe2 and TaSe2, reflecting the non-epitaxial structural relationship between the components. Each individual compound was addressed by sequentially depositing n layers of alternating elemental V and Se followed by m layers of alternating elemental Ta and Se in which the thickness of each pair of elemental layers was calibrated to yield a single-crystalline layer of the metal diselenide on annealing at low temperature for a short time. The structural changes during the transformation from initial reactant to crystalline superstructure are followed using X-ray diffraction. The structure of these nanoscale superstructures consist of an integral number of VSe2 and TaSe2 layers with minimal cation mixing between the layers. Electrical measurements show that all of the members of this family are metallic.