Additionally, to disentangle the effects of any hematite-type (V,Ni) 2 O 3 impurities in the title compound, the impurity phase was synthesized using the same precursor powders in an approximate NiO:V:V 2 O 5 molar ratio of 335:199:233 (V 1.33 Ni 0.67 O 3 ). The powders, totalling 0.5 g, were hand ground with a mortar and pestle under Ar before dry pressing and sealing in a quartz tube under vacuum. The sample was heated at 10 • C/min to 950 • C, the same temperature used by Rozier et al., for 48 h before cooling naturally with the furnace over roughly 3 h.