Ferrite Nanofibers Fabricated By Electrospinning:Its Microstructure And Magnetic Properties Research

Electrospinning was regarded as the simplest, versatile and general technology to generated untrothin and uniform nanofiber and various kinds of nanofiber could be prepared by the way of improving and changing electrospun set up and parameters, which are multidimensional nanofiber, nanowires, nanotubes, nanobelts, core-shell structure nanofiber, and the orientation and non-directional nanofiber.In this paper we use citric acid (C6H8O7) and glucose as a complexing agent, metal salt as the main materials, sol-gel method was adopted to prepare CoFe2O4nanopowders. We use citric acid (C6H8O7) and Dimethylformamide (DMF) as a complexing agent, metal salt as the main materials to prepare CoFe2O4nanofibers using electrospinning method. We prepare CoNdxFe2-xO4with rare earth elements Nd substitut at the B site of CoFe2O4. Taking cobalt nitrate, neodymium nitrate and cobalt nitrate as the raw material, and taking citric acid and DMF as a complexing agent to prepare CoNd0.05Fe1.95O4nanofibers by electrospinning method. Then we compare it with CoFe2O4.In experiments, temperature gravity anysis-differential thermal analyzer (TG-DTA), X-ray diffraction (XRD) and X-ray energy dispersive spectroscopy (EDS) were performed to analyisi the ferrite nanofiber structure and the composition of the sample. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to detected the morphology and structure of the nanofiber.The result shows that CoFe2O4xerogel could be changed to regular CoFe2O4nanopowder which is pure and good crystallization. The magnetic property is completely different between CoFe2O4powder and CoFe2O4fibers. The Coercivity of the powder sample is small which is22.51Oe and the saturation magnetization is larger, which are shows soft magnetic properties. While the Coercivity of the fibers sample is larger, which is458.17Oe and the saturation magnetization is smaller which are shows hard magnetic properties. The CoNd0.05Fe1.95O4were prepared by electrospinning method and substitution of B site. And the Nd3+was successfully substituted ending with pure and good crystallization. Favorable nanofiber could be prepared at500-900℃. The crystalline size of the particles were increased with the increasing of the annealing temperature. The coercive force, saturation magnetization and the residual magnetization were increased with the increasing of the grain size. While the Coercivity didn’t decrease at500-900℃. because of the CoNd0.05Fe1.95O4nanofibers has not reached the single critical size. Comparing with the experiment of Wang Zhongli with electrospinning method to prepare CoFe2O4nanofibers, the coercivity is the largest at700℃. The saturation magnetization, coercivity, remanent magnetization are increases by45.5%,16.1%, and74.6%, respectively.