摘要:
Different mass fraction of iron-containing silicon carbide(Fe/SiC)ceramics was successfully prepared by firstly synthesizing iron(Fe)-containing precursor via blending Fe colloids formed by the reaction of liquid polycarbosilane(PCS)and carbonyl iron with solid PCS and then the cross-linking and pyrolysis.The effects of the introduction of Fe on the component, structure, and magnetic and dielectric properties were systematically studied.When the mass fraction of iron is less than 8.94%, Fe element can significantly promote the decomposition of SiC xOyand generate β-SiC,and the crystallization peak of β-SiC is sharper with increased Fe.But when the Fe mass fraction increases to 11.78%, the main product is Fe3Si; Fe-SiC ceramics are all ferromagnetic,and their saturation magnetization increases exponentially with the increase of iron.Fe/SiC ceramic with 4.19%Fe has a minimum -9.4 dB reflection loss at 12.4 GHz.The bandwidths of less than -5 dB for Fe/SiC cermic with 4.19%and 8.94% Fe are 2.4 GHz and 3.7 GHz,respectively, which can be used as good microwave-absorption materials.%将羰基铁和液态聚碳硅烷(LPCS)反应生成的铁(Fe)溶胶与固态聚碳硅烷(PCS)混合,合成出不同Fe质量分数的 PCS 先驱体,然后经氧化交联和高温热解制备了不同 Fe 质量分数的磁性碳化硅陶瓷(Fe/SiC),系统地研究了Fe元素的引入对SiC陶瓷的组成、结构、磁性能和介电性能的影响规律.研究发现,当Fe质量分数小于8.94%时,在热解过程中,Fe元素可以显著促进SiCxOy的分解,生成β-SiC,且随着Fe质量分数的增加,β-SiC的结晶峰越来越强;但随着Fe质量分数继续增加,达11.78%时,则主要生成Fe3Si;Fe/SiC陶瓷均呈铁磁性,其饱和磁化强度随着Fe质量分数的增加而呈指数形式增加;当Fe 质量分数为4.19%时Fe/SiC陶瓷在12.4 GHz具有最小的反射损耗,为-9.4 dB,同时低于-5 dB的带宽为2.4 GHz,Fe质量分数为8.94%时,低于-5 dB的带宽则为3.7 GHz,可用作良好的微波吸收材料.