Preparation And Electromagnetic Performance Of Polyaniline/CoZn Ferrite Composites

In this thesis, Co0.8-xCrxZn0.2Fe2O4and Ni0.4Cr0.4Zn0.2CexFe2-xO4ferrites wereprepared by self-propagating combustion, PANI/Co0.7Cr0.1Zn0.2Fe2O4andPANI/Ni0.4Cr0.4Zn0.2Ce0.1Fe1.9O4compositeswere prepared by in situ polymerization.The products were characterized by X-ray diffraction(XRD), scanning electronmicroscopy (SEM), fourier transform infrared (FT-IR) spectrometer, ultraviolet-visible(UV-vis) spectrometer, vibrating sample magnetometer (VSM) and the vector networkanalyzer.It can be seen from the XRD pattern that Co0.8-xCrxZn0.2Fe2O4andNi0.4Cr0.4Zn0.2CexFe2-xO4ferrites are both cubic spinel structure, the minimum size are20.92nm and13.13nm, respectively. The the SEM pictures show that Co0.8Zn0.2Fe2O4and Ni0.4Cr0.4Zn0.2CexFe2-xO4are spherical, and has a degree of reunion.PANI/Co0.7Cr0.1Zn0.2Fe2O4and PANI/Ni0.4Cr0.4Zn0.2Ce0.1Fe1.9O4composites are neatmicrosphere structure. The VSM show that the magnetic parameter values Ms、Mr andHc of Co0.7Cr0.1Zn0.2Fe2O4ferrite are73.84emu/g,28.43emu/g and489.11Oe, greaterthan those of Co0.8Zn0.2Fe2O4values. The Ms、Mr and Hc of Ni0.4Cr0.4Zn0.2Ce0.1Fe1.9O4ferrite are81.53emu/g,32.58emu/g and453.42Oe, Ms and Mr are larger than those ofNi0.4Cr0.4Zn0.2Fe2O4Fe2O4values, but Hc is smaller. The Ms、 Mr And Hc ofPANI/Co0.7Cr0.1Zn0.2Fe2O4and PANI/Ni0.4Cr0.4Zn0.2Ce0.1Fe1.9O4composites are betweenPANI and ferrite. The result of vector network analyzer show that the real component ofdielectric constant e’ of Co0.8-xCrxZn0.2Fe2O4has maximum value when x=0.4, while thechange of the imaginary part of dielectric constant e” and reflection loss RLarerelatively small. For Ni0.4Cr0.4Zn0.2CexFe2-xO4ferrite, e’ has maximum value whenx=0.1, and e” has maximum value when x=0.2. The values of e’ and e” for the twocomposites are smaller than those of PANI, the minimum reflection loss appeared at thefrequency of18GHz. The results of XRD, FT-IR and UV-vis show thatPANI/Co0.7Cr0.1Zn0.2Fe2O4and PANI/Ni0.4Cr0.4Zn0.2Ce0.1Fe1.9O4are successfullysynthesized by in situ polymerization and there is interaction between PANI and ferrite.