Polyvinyl pyrrolidone nanofibers including nickel, zinc, and iron precursors were fabricated via the electrospinningmethod. To convert as-spun nanofibers to Ni0.5Zn0.5Fe2O4 o xide n anof ibers which is c apable o f shielding a n electromagneticwave, heat treatment conditions were optimized. To obtain the heat treatment condition that can exclude amorphous carbonblack and secondary crystal phase, samples were taken at each temperature while the calcination process and analyzed.
According to the X-ray diffraction (XRD) analysis, the Ni0.5Zn0.5Fe2O4 crystal phase started to appear from 300oC, but itwas confirmed through energy dispersive spectroscopy (EDS) analysis that heat treatment of 500oC or more was required toremove most of the carbon black. When the calcination temperature exceeds 650oC, crystal nuclei starts to grow and the fibersurface condition becomes rough, so it was confirmed that the heat treatment conditions should be selectively determinedaccording to the application field.