多铁性材料BiFe_(1-x)Co_xO_3的微波吸收特性研究

Study of Microwave Absorption Characteristics of Multiferroic Material BiFe_(1-x)Co_xO_3

用溶胶-凝胶法制备BiFe1-x Cox O3样品,用X射线衍射仪、扫描电镜、能谱分析对样品的结构、微观形貌、元素组成进行了表征,用微波矢量网络分析仪测试了样品在2～18GHz微波频率范围的复介电常数、复磁导率,并计算了损耗角正切及微波反射率。结果表明,当掺杂量x=0、x=0.1、x=0.2,煅烧温度800℃时,产物的主相为钙钛矿型BiFeO3,同时还有杂相Bi25FeO40,颗粒形貌为尺寸约1.5μm的立方形;Co的掺入有利于提高体系的微波吸收性能。当样品厚度为1.8mm,x=0.2时,吸收峰值为-26.5dB,带宽为2.08GHz,在高频段有良好的微波吸收,材料兼具介电损耗和磁损耗但介电损耗相对较强。

BiFe1-xCoxO3 samples were prepared by sol-gel process.The crystal structure,morphology and elements of samples were characterized by XRD,SEM and EDS.The complex dielectric constant and complex permeability of the samples were measured by microwave vector network analyzer,the loss tangent and microwave reflectivity were calculated in the frequency range from 2 GHz to 18 GHz.When the doping amounts were x =0,x=0.1,x=0.2 and the anneal temperature was 800 ℃,the major phase of product was BiFeO3 and minor phase was Bi25 FeO40,the particle morphology was cube with the size of 1.5μm.It was found that the microwave absorption of system is dramatically promoted.When d=1.8 mm,x=0.2,the absorption peak and effective band width is-26.5 dB and 2.08 GHz,it possesses excellent microwave absorption characteristics in high frequency.This material possesses dielectric loss and magnetic loss at the same time,but the former is relatively stronger.