The Preparing Process And The Application Research Of Rare Earth Doped Spinel Ferrite

In this work, rare earth doped spinel ferrite was prepared by using LCS method.The product was characterized by X-ray diffraction analysis (XRD), Infrared Spectroscopy (FT-IR) and Transmission Electron Microscopy (TEM).The effect of assistants and other process conditions on the products were researched. Then the optimal conditions of preparing were studied.Firstly, the fuel systems of amino-nitrate and amide nitrate are improved by adding complex agent and dispersant.The results show that the sample size is large when using amino fuel, and it is easy to agglomerate and produce a small amount of iron oxide because of the high combustion temperature; instead, the sample size is small,the products have better dispersivity and the crystal is more perfect when using the amide fuel as the reducing agent, which due to its larger discharge capacity and complexation. Finally, the effect of operation conditions were studied and found the optimal properties of preparing each 1g products were as follows:2gEDTA, 1g glycol and the calcination temperature is 800℃.Then the ammonium perchlorate (AP) is mixed with Ni0.5Fel-xCex02 which is prepared by the improved LCS method. The thermal decomposition of AP process were analyzed through differential scanning calorimetry (DSC). It is found that with the increase of metallic oxide, the peak of AP low temperature decomposition move up a little, but that of high-temperature decomposition decreased significantly.Recording to the analysis, the rare earth compounds have negative effect on low temperature decomposition of AP and have positive effect on the high thermal decomposition reaction of AP. The activation energy of Nio.5Fe0.91Ceo.09O2 is calculated separately by Kissinger, Flynn-Wall-Ozawa and Friedman methods. We find that the Ozawa calculation is best out of comparing these methods. When the dopant ratio is 0,0.03,0.06 and 0.09, the mean activation energy is 83.86,89.75,90.32,93.73kJ/mol respectively.Compare the effect of rare earth element doped spinel ferrite on 3mm with 8mm radar wave. The results are as follows:with the particle size increase, it is in favor of 3mm radar wave absorption, and for 8mm radar wave particle, it reaches a maximum absorption value as the particle diameter is 46.1 nm. The rare earth element cerium doped diminishes the magnetism of Nio.5FeO2, so it is not conducive to the radar wave absorption.