Dy掺杂Bi1-xDyxFeO3多铁性材料微波电磁特性研究

采用溶胶-凝胶法制备Dy掺杂的Bi1-xDyxFeO3多铁性材料,利用XRD,SEM对材料物相、微结构及形貌进行表征分析;分别采用传输/反射法和弓形法,借助微波矢量网络分析仪测量系统,测量材料试样的微波电磁参量及吸波性能.在实验研究煅烧温度对材料微结构和形貌影响的基础上,确定最佳煅烧温度,进而探讨Dy掺杂量对Bi1-xDyxFeO3材料的微结构、复介电常数和复磁导率频谱特性、电磁损耗机制以及微波吸收性能的影响.结果表明:850oC的煅烧温度制备的Bi1-xDyxFeO3材料杂相基本消失,材料颗粒为亚微米尺寸的短纤维状;Dy掺杂能有效抑制材料中杂相形成和煅烧过程Bi3+挥发,有助于抑制螺旋形自旋磁结构,从而提高复介电常数实部和虚部,增强磁谱的弛豫特性;Bi1-xDyxFeO3材料中介电损耗和磁损耗两种机制共存且存在竞争与协同效应,Dy掺杂可以改善Bi1-xDyxFeO3材料微波高频段的吸波性能.

Electromagnetic Characteristics of Multiferroic Dy-doped Bi1-xDyxFeO3 in Microwave Range

Multiferroic Bi 1-x Dy x FeO 3 with different amounts of doping Dy was prepared in the Sol-gel method.The phase,microstructure and morphology of the samples were characterized with XRD and SEM,respectively.The electromagnetic parameters and microwave absorbing properties were measured respectively in transmission / reflection technique and arc method under the network analyzer system.The optimal calcined temperature was confirmed on the basis of the analysis on the effects of calcined temperatures on microstructure and morphology.Further studies were carried out with regard to the influences of Dy-doped contents on microstructure,complex permitivity and permeability,electromagnetic loss mechanism and wave absorbing properties.The results indicate that the particles are short fibers in submicron and impurity phases disappear under the calcined temperature of 850℃.The doped Dy can effectively re-strain the formation of the impurity phase,volatilization of Bi 3+,and spiral spin magnetic structure.Therefore,the complex permitivity and relax strength of the permeability spectra are improved.Due to the coexistence and competition of dielectric and magnetic loss mechanism,Bi 1-x Dy x FeO 3 with doping Dy can improve absorbing ability in high frequency ranges.