NiCo铁氧体的sol-gel自蔓延法制备及电磁性能

Electromagnetic properties of NiCo ferrite prepared by the sol-gel self-combustion method

为了提高NiCo铁氧体Ni1–xCoxFe2O4(x=0,0.1,0.3和0.5)的抗电磁干扰特性,采用柠檬酸sol-gel自蔓延法制备了纳米晶粒的NiCo铁氧体样品。利用XRD、VSM和矢量网络分析仪,测定了样品的晶体结构和磁性能及电磁性能。结果表明:在0.1～1.5GHz频段,Co含量x=0.1时样品的tanδ比x=0时提高了一倍以上。但Co含量的进一步增加却使样品的损耗特性变差,例如x=0.5时的tanδ仅为x=0时的40%,这与Co2+占位和晶粒度大小有密切关系。

To improve the anti-EMI performance of NiCo ferrite Ni1–xCoxFe2O4（x=0,0.1,0.3 and 0.5）,nanosized NiCo ferrite crystalline grains were prepared by the sol-gel self-combustion method.The crystal structure,magnetic properties and electromagnetic properties of obtained samples were studied with XRD,VSM and Vector Network Analyzer.The results show that,in the frequency range of 0.1～1.5 GHz,the tanδ of samples is doubled when the Co content increases from 0 to 0.1.However,the loss performance of samples becomes worse with the further increase of Co content.For example,the tanδ of sample with x=0.5 is 40% lower than that of sample with x = 0.This relates to the occupied sites of Co2＋ and the crystalline grain size.