Fabrication and characterization of micro-pattern dandelion-like and nanobelts of β-SrV2O6 via hydeothermal process

Dandelion-like micro-crystallites and long belt-like nanostructures of Sr-V-O materials were synthesized under mild hydrothermal reaction conditions in the presence of mineralizer adipic acid at 220 degrees C for 60 h and 180 degrees C for 60 h, respectively. Scanning electron microscopy measurements show that the Sr-V-O micro-crystallites in general consist of well-arranged microrods with the average length of a few hundred micrometers and diameters ranging from 1 urn to 5 mu m. The long belt-like nanostructures around 100 run in width exhibit visible twist and waving in shapes, showing high flexibility in nature. Powder X-ray diffraction and electron diffraction measurements both revealed that these micro-/nanometer materials have an orthorhombic structure with the lattice parameter a=9.694 (A) over circle, b=3.687 (A) over circle, and c=12.570 (A) over circle (space group of Puma) as reported for beta-SrV2O6 phase. The electron diffraction patterns also indicate that the micro-/nanometer beta-SrV2O6 crystallites preferentially grow along the (010) crystallographic direction. The effects of the hydrothermal treating temperature and chemical compositions ratio of Sr to V on the morphologies of the final products are extensively investigated. A possible crystallite growth mechanism for the micro-pattern formation is proposed based on the systematic analysis of the experiental results.