Modification in crystal structure of copper ferrite fiber by annealing and its hyperthermia application

The copper ferrite fiber has been synthesized using the electrospinning technique by optimizing the electric voltage and viscosity of the polymer solution. Physical properties of copper ferrite fiber have been tuned with annealing at different temperatures (550, 750, and 950 °C for 2 h). The crystal structure has been confirmed by X-ray-diffraction pattern analysis and studied by using Rietveld refinement technique. The morphology of fibers was explored with the help of field emission scanning electron microscopy. The fibers annealed at 550 °C crystallize to cubic structure, and the tetragonal phase has been observed for 750 °C, and 950 °C annealed fibers. Sample annealed at 750 °C shows the highest magnetocrystalline anisotropy constant at 300 K (3 × 10 5 erg/cc). The SAR (Specific absorption rate) and ILP (intrinsic loss power parameter) of the 750 °C annealed fibers are 265 ± 5 W/g and 3.412 nHm 2 /Kg, respectively. The SAR value calculated by using non-adiabatic approach is 335 W/g.