Based on a W18O49 nanowire template, iron-substituted W18O49 nanowires and FeWO4 ferberite flowers have been generated by using mixed FeCl3 and WCl6 at different ratios in a simple solvo-thermal process employing cyclohexanol as the solvent. Detailed characterization by electron microscopy and spectroscopy has shown that increasing the FeCl3 concentration during solvo-thermal synthesis promotes a morphological evolution from the long one-dimensional nanowires of the precursor through short Fe-containing W18O 49 nanowires and two-dimensional platelets to three-dimensional flowers with sixfold symmetry. The driving force for these transformations is attributed to Fe inclusion in the W18O49 template at low Fe concentrations, which introduces internal stresses to the W 18O49 nanowires. At high Fe concentrations, close to the stoichiometric composition of FeWO4, the formation of the flower is triggered by the intrinsic sixfold symmetry of crystalline ferberite, via a combination of initial nanoblade nucleation and the competing self-assembly of neighboring parallel nanoblades. A similar solvo-thermal process has also been successful in the synthesis of MnNb2O6 bronze flowers, which exhibit structures with a morphology resembling a purposely carved microgear. Photoluminescent and magnetic properties of the products are also investigated.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry