Fabrication and characterization of cobalt ferrite (CoFe2O4) nanofibers by electrospinning

By sol–gel process and electrospinning method, cobalt ferrite/polyvinyl acetate (PVAc) composite fiber was obtained. Cobalt ferrite (CoFe2O4) nanofibers were synthesized by calcination of the cobalt ferrite/polyvinyl acetate (PVAc) composite fiber with several temperatures. The nanofibers were characterized by SEM, FT-IR, XRD and EXAFS. The diameter of nanofibers was slightly decreased with increasing the calcination temperature. The fibers calcined at 800 °C ranged from 100 to 225 nm with an average diameter of 175 nm, and changed as the typically continuous crystallites with the complete decomposition of PVAc. The morphology of cobalt ferrite corresponded with cubic spinel structure as a result, analyzed by XRD and EXAFS. In a result of EXAFS analysis, the coordination number of metal showed the trend about 12 atoms to the neighbor of Fe and Co. It is clearly coincided with theoretical values that 8 oxygen atom and 12 metal atoms in the neighbor structure of Fe and Co. Also, the magnetic properties of the calcined samples were characterized by using a vibrating sample magnetometer (VSM).