Synthesis and structure of strontium ferrite nanowires and nanotubes of high aspect ratio

Strontium hexaferrite nanowires and nanotubes were synthesized in porous anodic aluminum oxide templates. Different solution-based synthesis techniques (spin coating, vacuum suction, and dip coating) were investigated. Strontium ferrite nanopowders were also synthesized by a similar sol–gel process. The morphology, structure, and composition of the embedded hexaferrite nanostructures were examined by field emission scanning electron microscope, X-ray diffraction, and transmission electron microscopy. Strontium ferrite wires with Fe/Sr ratios from 10 to 12 under different annealing temperatures of 500–700 °C were studied. The results showed that dip coating could produce fine and uniform strontium ferrite nanowires. The ratio of Fe/Sr of 11 and a calcination temperature of 650 °C were found to be optimum conditions. The produced material may be of importance for novel microwave-frequency nanoscale devices. Graphical Abstract