Dielectric, magnetic and microwave absorbing properties of polyaniline-Co_0.7Cr_0.1Zn_0.2Fe₂O₄ composites

Rui-Ting Ma，Huai-Yu Shang，Xiao Wang，Dan Jiang

School of Materials Science and Engineering,Shenyang Ligong University

摘 要：The spinel cobalt chromium zinc ferrites(Co_0.7Cr_0.1Zn_0.2Fe₂O₄) and the polyaniline（PANI）-(Co_0.7Cr_0.1Zn_0.2Fe₂O₄ composites were prepared by polyacrylamide gel and an in situ polymerization method,respectively.The structure of the synthesized material was characterized by X-ray diffraction（XRD） and Fourier transform infrared spectrometer（FTIR）,which shows that the spinel Co_0.7Cr_0.1Zn_0.2Fe₂O₄ ferrites and the PANICo_0.7Cr_0.1Zn_0.2Fe₂O₄ composites are obtained.As a small amount of Co²⁺ in the octahedron ferrite is replaced by Cr³⁺,the lattice constant of Co_0.8Zn_0.2Fe₂O₄ ferrites reduces from0.8409 to 0.8377 nm.The magnetic properties of the two materials were investigated by vibrating sample magnetometer（VSM）.The VSM results confirm that the saturation magnetization（M_s）,remanent magnetization（M_r） and coercive force（H_c） of the PANI-Co_0.7Cr_0.1Zn_0.2Fe₂O₄composites are 8.80 mA·m²·g^-1,3.14 mA·m²·g^-1 and37.22 kA·m^-1,respectively,which are smaller than those of the Co_0.7Cr_0.1Zn_0.2Fe₂O₄ ferrites.The microwave absorbing capability of the two materials was studied by waveguide method.In the frequency range of 5-20 GHz,two reflection loss maximum values of the PANI-Co_0.7Cr_0.1Zn_0.2Fe₂O₄composites appear at 14.1 and 17.9 GHz with-13.17 and-15.36 dB,respectively,which are obviously higher than those of the Co_0.7Cr_0.1Zn_0.2Fe₂O₄ ferrites.

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