Role of Oxygen Vacancies in the Electrical Properties of WO_3−x Nano/Microrods with Identical Morphology

Figure 1

XRD (a) and XPS (b) patterns of the obtained samples. The samples were prepared by thermal evaporation of 1 g WO₃ powder and different amounts of S powders (0.1–0.5 g) at 1150°C separately. The results indicate that pure WO₃, WO_2.90, W₁₉O₅₅, and W₁₈O₄₉ crystals could be obtained, when the applied amount of S was 0.1, 0.15, 0.2, and 0.5 g of S, respectively.

(a)

(b)