Influence of interstitial V on structure and properties of ferecrystalline ([SnSe]1.15)1(V1+xSe2)n for n=1, 2, 3, 4, 5, and 6

A series of ferecrystalline compounds ([SnSe]1.15)1(V1+xSe2)n with n=1–6 and a thin film V1+xSe2 were synthesized utilizing the modulated elemental reactant technique. The effect of interstitial V-atoms ranging from 0.13≤x≤0.42 in different compounds on structure and electrical properties of these intergrowth compounds is reported. The presence of the interstitial V-atoms for n>1 was confirmed by Rietveld refinements as well as HAADF-STEM cross sections. The off-stoichiometry in the thin film V1.13Se2 causes a suppression of the charge density wave, similar to the effect of non-stoichiometry observed for the bulk compound. The charge density wave of ([SnSe]1.15)1(V1+xSe2)1, however, is not affected by the non-stoichiometry due to its incorporation as volume inclusions or due to the quasi 2-dimensionality of the isolated VSe2 layer. In the compounds ([SnSe]1.15)1(V1+xSe2)n with n=2–6, the temperature dependence of the electrical resistivity approaches bulk-like behavior.