posted on 2016-06-14, 12:23authored byHicham Moutaabbid, Yann Le Godec, Dario Taverna, Benoı̂t Baptiste, Yannick Klein, Geneviève Loupias, Andrea Gauzzi
By means of high-pressure
synthesis in the 4–6 GPa range, we report on the successful
growth of high-quality 1T-V1+xS2 single crystals with controlled concentration, x = 0.09–0.17, of self-intercalated V atoms in the
van der Waals gap. A systematic X-ray diffraction and energy-dispersive
X-ray spectroscopy study unveils a linear decrease of x with the synthesis pressure, dx/dP = −0.042 GPa–1, suggesting that the stoichiometric
(x = 0) phase is stable above 8 GPa. Transmission
electron microscopy and electrical resistivity measurements show that,
for all x values studied, the system is metallic
up to 400 K, with no charge-density-wave order, contrary to the x = 0 composition. This finding clarifies the controversial
electronic phase diagram of the 1T-V1+xS2 system and unveils a connection between
the charge-density-wave phase observed at x = 0 and
the itinerant antiferromagnetic phase stable for x > 0.25.