磁场对Ni/硅橡胶复合材料交流电导率及介电性质的影响  

Influence of magnetic field on the AC conductivity and dielectric properties of Ni/silicone rubber composite

作　　者：常方高[1,2] 王丹丹[1,2] 胡棚[1,2] 杨枫[3] 宋桂林[1,2] 

机构地区：[1]河南师范大学物理与信息工程学院,新乡453007 [2]河南师范大学河南省光伏材料重点实验室,新乡453007 [3]河南科技学院高等职业技术学院,新乡453003

出　　处：《复合材料学报》2010年第5期13-18,共6页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金资助项目(60571063);教育部留学回国人员科研启动基金资助项目(教外司留[2005]55);河南省教育厅自然科学研究项目(2006140004)

摘　　要：采用硅橡胶(110型)与金属(镍粉)按质量比为1∶2.7进行配料,应用室温二次固化合成Ni/硅橡胶压敏复合材料样品。室温下测量了样品的压阻效应,比较了外加0.024 T磁场前后样品的介电性质。结果表明,当压强从3.75 kPa到312.5 kPa时,样品直流电阻率下降了8个数量级。与加磁场前相比,0.024 T的磁场使得低频(40～104Hz)交流电导率提高了2.46倍,介电常数提高了20%,介电损耗提高了2倍,这主要是由复合材料中铁磁-绝缘体-铁磁颗粒膜的隧道磁电阻效应以及磁电耦合引起的。撤去磁场后交流电导率、介电常数和介电损耗均不能回到加磁场前的初始值,这与Ni粉的铁磁性有关。Ni/硅橡胶压敏复合材料的压阻、磁电阻效应及磁电耦合等物理性质在磁传感器件、信息储存等领域有潜在的应用价值。Ni-silicone rubber composites were prepared with the metal（Ni） and silicone rubber（110） by a mass ratio of 2.7∶1 using a room-temperature twice cure method.At the room temperature,the sample＇s piezoresistive and dielectric properties were measured before and after applying a 0.024 T magnetic field.The results show that when the uniaxial force increases from 3.75 kPa to 312.5 kPa,the sample＇s resistivity decreases 8 orders of magnitude.Compared with the values measured before applying the magnetic field,the AC conductivity at low frequencies（40～10^4 Hz） increases 2.46 times,the dielectric constant increases 20% and the dielectric loss increases 2 times by the action of a 0.024 T magnetic field.This is mainly caused by the composite＇s tunneling-magnetoresistance and magnetoelectric coupling effect.After taking away the magnetic field,conductivity,dielectric constant and dielectric loss could not go back to the initial values,which has something to do with the ferromagnetism of Ni powders.Ni-silicone rubber pressure-sensitive composites have potential applications in magnetic sensors and information storage with the properties of piezoresistive,TMR and magnetoelectric coupling effects.

关 键 词：金属/高分子复合材料 压阻效应 磁场 电导 介电性质 

分 类 号：O469[理学—凝聚态物理] TB332[理学—电子物理学]