W18O49 nanorods: Controlled preparation, structural refinement, and electric conductivity

Highlights: • W₁₈O₄₉ nanorods were controlledly synthesized using pyrolysis-reduction process. • The cell parameters of W₁₈O₄₉ are obtained by the Rietveld refinement. • The sheet resistance of pure W₁₈O₄₉ nanorods was analyzed. This paper reports on the controlled synthesis of W₁₈O₄₉ nanorods using pyrolysis-reduction process through tuning both H₂ gas flow and heating temperature. The results suggest that W₁₈O₄₉ nanorods will grow well when calcined at 650 °C for 2 h at 10 l/h H₂ gas flow rate. Using GSAS software the fitted lattice parameters of obtained W₁₈O₄₉ are given, that is, a: 18.340 Å, b: 3.788 Å, c: 14.025 Å, β: 115.168°, by the Rietveld refining X-ray diffraction pattern. The result of sheet resistance measurement of samples indicates that pure W₁₈O₄₉ nanorods exhibit a resistivity as low as 0.068 Ω·cm.