Fe-doped In₂O₃/α-Fe₂O₃ core/shell nanofibers fabricated by using a co-electrospinning method and its magnetic properties

We report on the fabrication and magnetic properties of Fe-doped In ₂O₃/α-Fe₂O₃ core/shell nanofibers (NFs) by co-electrospinning method. The structural investigations showed that the core and shell materials were composed of crystalline Fe-doped In₂O₃ NFs and α-Fe₂O₃ nanoparticles with a size of less than 1 μm, respectively, and the morphologies of the resultant NFs changed with variation of the relative source ratio of In to Fe (the In/Fe molar ratio). Interestingly, X-ray diffraction and X-ray photoelectron spectroscopy results showed that the Fe elements were incorporated into the In₂O₃ lattice, causing a modification of the magnetic properties of the In₂O ₃/α-Fe₂O₃ core/shell NFs. Investigations of the magnetic properties of the core/shell NFs showed enhanced magnetic properties, and an increase in saturation magnetization values with an increased In/Fe molar ratio. Based on our results, we suggest three mechanisms for the enhancement of magnetic properties that result from our proposed structures.