超导-高分子复合材料介电性质的研究  

ELECTRICAL PROPERTIES OF THE SUPERCONDUCTOR-POLYMER COMPOSITES

作　　者：宋桂林[1] 房坤[1] 常方高[1] 

机构地区：[1]河南师范大学物理与信息工程学院,河南新乡453007

出　　处：《低温物理学报》2008年第3期222-226,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:60571063)资助的课题;教育部留学回国人员科研启动基金(批准号:教外司留[2005]55)资助的课题;河南省教育厅自然科学研究计划(批准号:2006700014)~~

摘　　要：采用固相反应法制备高温超导材料Bi2Sr2Ca2Cu2O3(Bi-2223),以高温超导材料为基体加入聚乙丙烯橡胶(EPR)高分子绝缘材料,通过不同温度退火处理,制备一系列超导-高分子复合材料,运用X射线衍射技术(XRD)和扫描电镜(SEM)对样品进行物相分析;采用低温循环系统测量样品电阻随温度变化关系;利用HP4294A型阻抗分析仪测量样品的介电特性,并对样品的电输运性质和介电特性进行了探讨.实验结果表明:对于掺杂质量为10%EPR样品随着退火温度的升高,其XRD衍射强度和衍射半峰宽度有所增加,其电阻明显降低.样品A电阻随着测量温度的降低而增大,表现出半导体特性;样品B,C,D电阻随测量温度的降低而减小,样品B不具有超导电性,样品C,D表现出明显的超导电性,其超导转变温度分别是90K和95K.室温下,样品的介电常数及介电损耗均随频率增大而减小,介电常数随退火温度的升高而减小,介电损耗却随退火温度的升高而增大,介电特性这种变化规律与样品电阻的变化有直接的关系.The superconductor-polymer composites of high temperature superconductor （ Bi-2223 ） and ethylene propylene rubber （EPR） have been prepared by conventional solid-state reaction method. The XRD, SEM, the resistivity and dielectric property of the metal-polymer composite are also studied. The dielectric and electrical transport properties of the superconductor-polymer composite are investigated. The phase structure of the composite was characterized by using X-ray diffraction （XRD） and scanning electron microscopy （SEM） technique. Doping with 10wt% of EPR has reduced the peak intensities. The resistivity of the superconductor-polymer composite samples was measured between 50K and 30OK. The results indicate that the room resistivity of the superconductor-polymer composite decreases with increasing annealing temperature. The superconductor-polymer composites show the signs of superconducting transition at an annealing temperature of 800 ℃. The dielectric properties of the superconductor-polymer composite samples were measured. Experimental result indicates that dielectric constant and the dielectric loss of the superconductor-polymer composite decreases with increasing frequency, the dielectric constant of the composites decrease with increasing annealing temperature. Yet the dielectric loss of composites increases with increasing annealing temperature.

关 键 词：超导-高分子复合材料 输运性质 介电特性 

分 类 号：O511[理学—低温物理]