基于氧化铁颗粒与聚合物的纳米复合材料磁电容特性研究  

Magnetodielectric Effect in Magnetite-Polymer Nanocomposites

作　　者：陈国彬[1,2] 张晓明[1] 刘俊[1] 吕忆玲 

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室电子测试技术国家重点实验室,太原030051 [2]中北大学仪器与电子学院,太原030051

出　　处：《高分子学报》2015年第3期277-283,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51375463)资助项目

摘　　要：对由Fe3O4纳米颗粒-聚二甲基硅烷(PDMS)聚合物材料所组成纳米复合材料磁电容特性进行了研究,提出了该复合材料的制备方法,并对其进行了表征、磁化特性测试以及零磁场环境下介电特性测试;分析了该复合材料的相对介电常数随环境磁场的变化关系以及具有不同含量、粒径纳米颗粒的复合材料磁电容特性差异.实验结果显示,该复合材料的相对介电常数随环境磁场的增大而增大,其变化曲线有一定的滞后特性;复合材料的相对介电常数变化量随材料中纳米颗粒粒径以及含量的增大而增大,但含有较大颗粒复合材料的相对介电常数变化曲线具有较大的滞后性.研究表明,该复合材料在环境磁场中能够产生磁电容效应,其相对介电常数随环境磁场的变化率、饱和值以及滞后性都会受到材料中包含的纳米颗粒的含量以及磁化特性(磁导率、饱和磁化强度、矫顽力)所影响.The magnetodielectric effect of Fe3O4 nanoparticles and polydimethylsiloxane（ PDMS）nanocomposites is reported. The fabrication method of nanocomposites is proposed,and a series of tests on composites including structural characterization,magnetic properties,dielectric properties are performed. It can be concluded that the magnetic properties of the composites depend on the nanoparticle＇s magnetization. The dielectric constant of the composites with zero magnetic field is increasing with the increase of the nanoparticle concentration,which is consist with the Maxwell-Wagner model. The variation mechanism of relative permittivity as a function of applied magnetic field and the magnetodielectric effect of nanocomposites with different sizes and concentrations of nanoparticles are mainly investigated. The results show that the variation of difference relative permittivity with hysteresis is increasing with the increase in magnetic field. The nanocomposites relative permittivity variation with magnetic field increases as increasing the concentration and the size of nanoparticles. However,the permittivity variation hysteresis of the nanocomposites with bigger nanoparticles is also larger. The studies confirm that the magneticdielectric effect can be observed when the composites are placed in magnetic field,and the variation rate,saturation and hysteresis of the nanocomposites relative permittivity with magnetic field are affected by the concentration and the magnetic properties of nanoparticles including permeability,saturation magnetization and coercivity.

关 键 词：磁电容 氧化铁纳米颗粒 纳米复合材料 聚合物 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TB332