Anosovite-Type V3O5: A New Binary Oxide of Vanadium

The reaction of either V2F6 center dot 4H(2)O or a mixture of 60 wt % VF2 center dot 4H(2)O and 40 wt % VF3 center dot 3H(2)O with a water-saturated gaseous mixture of 15-20 vol % hydrogen in argon leads to the formation of a new polymorph of V3O5 crystallizing in the orthorhombic anosovite-type structure. Quantum-chemical calculations show that the anosovite-type structure is about 15 kJ/mol less stable than the corresponding monoclinic Magneli phase. In addition, there are no imaginary modes in the phonon density of states, supporting the classification of the anosovite-type phase as a metastable V3O5 polymorph. Susceptibility measurements down to 3 K reveal no hint for magnetic ordering.