The h‐SbxWO3+2x Oxygen Excess Antimony Tungsten Bronze.

We describe the previously unreported oxygen excess hexagonal antimony tungsten bronze is reported, with a composition of Sb0.5W3O10, in the following denoted as h‐SbxWO3+2x with x=0.167, to demonstrate its analogy to classical AxWO3 tungsten bronzes. This compound forms in a relatively narrow temperature range between 580 °C<T<620 °C. It was obtained as a dark‐blue polycrystalline powder, and as thin, needle‐shaped, blue single crystals. h‐SbxWO3+2x crystallizes in the hexagonal space group P6/mmm with the cell parameters a=7.4369(4) Å and c=3.7800(2) Å. The antimony and excess oxygen occupy the hexagonal channels within the network of corner‐sharing WO6 octahedra. h‐SbxWO3+2x has a resistivity of ρ300 K≈1.28 mΩ cm at room temperature, with little if any temperature‐dependence on cooling. DFT calculations on a simplified model for this compound find a metallic‐like electronic structure with the Fermi level falling within rather flat bands, especially around the Γ point. Tungsten bronzes are a class of insertion compounds consisting of a network of corner‐sharing [WO6] octahedra. There has been a logical deficiency in the structural chemistry of antimony tungsten bronzes, which is now bridged with the here reported discovery of a hexagonal tungsten bronze h‐SbxWO3+2x with x=0.167. This blue, metallic bronze consists of [SbO2]+ chains along the hexagonal channels. [ABSTRACT FROM AUTHOR]