Tungsten oxide tree-like structures

摘要: Abstract An interesting micrometer scale tree-like structure has been generated by heating a W foil, partly covered SiO 2 plate, in an Ar atmosphere at ca. 1600°C. Upon sonication, the trees are broken into nanoneedles (ca. 5–50 nm wide and 20–200 long) planar polyhedral nanoparticles 10–50 cross-section). Structural analysis, using ED, EDX, XRD, HRTEM, showed that: (1) consist of well-crystallised WO x phases ( =0–3); (2) composed mainly monoclinic 18 O 49 phases; (3) primarily 3 . The tree growth is thought to arise from intrinsic crystalline feature , defect or shear which responsible for breakdown trees.