Figure 1.
Scanning electron micrographs of study powders: "as-received" (A) W metal, (B) Co metal, (C) WO3, (D) WO2.98, (E) WO2.81, (F) WO2.66, and (G) WO2.51 powders. The W and Co powders were agglomerates of primary particles, the WO3 and WO2.98 powders were cube-shaped isometric particle morphology, and the WO2.81, WO2.66, and WO2.51 powders were mixtures of fiber- and cube-shaped particle morphologies; "dispersed" (E1) WO2.81, (F1) WO2.66, and (G1) WO2.51 powders illustrating individual fiber morphology. Note that the scale bars differ among images.