Structural, transport and electronic properties of a layered dichalcogenide AuVS2 with semimetallic properties

We report on preparation, crystal structure, transport properties, and ab initio band-structure calculations of the layered compound AuVS2. Single crystals of submillimeter size are obtained by reacting powders of BaVS3 with metallic gold at 700 °C under an hydrostatic pressure of 3 GPa. According to single-crystal x-ray-diffraction data, the crystal structure is hexagonal with unit-cell parameters a5b53.22460.001 Å, c515.03960.002 Å, and space-group symmetry P63 /mmc. Temperature-dependent ac resistivity measurements yield a value of room-temperature in-plane resistivity %ab'400 mV cm and show a slightly metallic temperature dependence above 250 K. Below this temperature the dependence becomes weakly insulating but the resistivity remains &800 mV cm at 4.2 K. This behavior is in agreement with the above band-structure calculations which indicate that AuVS2 is a semimetal with an almost vanishing density of states at the Fermi level. Both electron and hole doping would strongly enhance the metallic properties and change the very small Fermi surfaces of the undoped compound into larger pockets with mostly V 3d character.