Preparation And Performance Of Nano Fe₃O₄ Composite Absorbing Materials

Ferroferric oxide?Fe₃O₄?is a kind of spinel ferro-magnetic materials,in the microwave band area,the incident electromagnetic wave can generate magnetic loss,it also can generate electricity loss again,Fe₃O₄ is a kind of double medium.But single ferroferric oxide absorbing materials cannot meet requirement of material“thin,light,wide and strong”,so this topic on the ferroferric oxide was modified via series of method such as adulterating,compounding,electroless plating in order to improve the ferroferric oxide?0-6000 MHz?in low frequency area of microwave absorption performance.The detailed research methods and contents are as follows:?1?Aqueous solution method at low temperature and precipitation method were used to synthesize the ferromagnetic oxide powder,test the absorbing performance of the ferroferric oxide,select the aqueous solution method at low temperature as ferroferric oxide preparation of the optimal solution.?2?Fe₃O₄/ZnO compounds were prepared via hydro-thermal method,The composites were characterized by X-ray diffraction?XRD?,energy spectrum analyzer?EDS?and scanning electron microscope?SEM?.The characterization results showed that the preparation of the different ratio of Fe₃O₄/ZnO powder,test the microwave absorbing properties of the different mole ratio.Absorbing performance testing of mole ratio of n?Fe₃O₄?:n?ZnO?=2:1composites has the best performance.?3?Fe₃O₄/ZnO/PAn composites were prepared via in-situ polymerization.The composites were characterized by XRD,EDS,SEM,TEM and IR.The test results showed that the preparation of the different component proportion of Fe₃O₄/ZnO/PAn composites,test the different proportion of composition on the properties of absorbing effect.?4?Various of elements mole ratio of Fe-Co-Ni iron powder prepared via liquid phase reduction.Different mole ratio of iron series elements of alloy powder characterized by XRD,SEM,EDS.Test the metal wave absorption performance of different mole ratio of concentration of citric acid in the preparation,mole ratio of Co:Ni=1:2 in the alloy micropowder has the maximum value at-34.4dB.?5?Electroless plating FeCoNi iron on the surface of Fe₃O₄ was performed at different process parameters via Tollens' reagent as sensitization-activator.Examines the temperature and pH value and reaction on the process of electroless plating and the influence of the microwave absorption property.Finally,the reaction mechanism of palladium-free electroless plating was analyzed.Condition in the pH=9,reaction temperature is 80?,reaction time is 6hours,mole ratio of Co:Ni=1:1 has the best absorbing performance.