Densely packed single-crystal Bi2Fe4O9 nanowires fabricated from a template-induced sol–gel route

Densely packed single-crystal Bi2Fe4O9 nanowires were successfully synthesized by a template-induced citrate-based sol–gel process. The structural properties of the nanowires were characterized using many techniques. The results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that Bi2Fe4O9 nanowires possessed a uniform length and diameter, which were controlled by the thickness and the pore diameter of the applied porous anodic aluminum oxide (AAO) template, respectively. The results of X-ray diffraction (XRD) and the selected area electron diffraction (SAED) indicated that Bi2Fe4O9 nanowires had an orthorhombic single-crystal structure. Furthermore, the energy-dispersive X-ray (EDX) spectroscopy demonstrated that the stoichiometric Bi2Fe4O9 was formed. The possible formation mechanism of nanowires was also discussed.