Effect of Calcination Temperature on Microstructure and Microwave Absorbing Property of Ni0.5Zn0.5Fe2O4 Micro/nanofibers

The Ni0.5Zn0.5Fe2O4/PVP composite micro/nanofibers with average diameters of around 300 similar to 500nm are prepared by sol-gel method combined with electrospinning technology. The influences of the calcination temperatures (800 degrees C, 900 degrees C, 1100 degrees C) on the crystal structure, micromorphology and microwave absorbing property of the calcined products are characterized by means of XRD, FT-IR, SEM and vector network analyzer. The results show that the pure spinel structure of Ni0.5Zn0.5Fe2O4 are all formed when the composite micro/nanofibers are calcined at above 800 degrees C. With the increase of calcination temperature, the Ni0.5Zn0.5Fe2O4 grains gradually grow up in which the micro/nanofibers were contained, and the micro/nanofiber morphology changes toward the bamboo-like structure, and eventually loses the fiber morphology and presents the irregular granlar forms. In the band of 2 similar to 18GHz, the minimum reflectivity of the products moves to high frequency gradually. The microwave absorbing property of the products being calcinated at 800 degrees C is better than that of being calcinated at 900 degrees C and 1100 degrees C.