Cu含量对BaTiO_3/Cu复相陶瓷材料介电性能的影响  

Effect of Cu Content on Dielectric Properties of BaTiO_3/Cu Composite Ceramics

作　　者：蒲永平[1] 许宁[1,2] 王博[1] 吴海东[1] 陈凯[1] 

机构地区：[1]陕西科技大学材料科学与工程学院,西安710021 [2]陕西科技大学教育部轻化工助剂化学与技术重点实验室,西安710021

出　　处：《无机材料学报》2011年第2期175-179,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(51072106);教育部科学技术研究重点项目(209126);陕西省科技攻关项目;陕西省教育厅科研专项基金(112H011);陕西科技大学研究生创新基金~~

摘　　要：用传统固相法制备了（1-x）BaTiO3/xCu（x=5 wt%,10 wt%,15 wt%,20 wt%,25 wt%,30 wt%）复相陶瓷,研究了Cu含量对复相陶瓷材料的显微结构、渗流阈值及介电性能的影响.研究结果表明：BaTiO3/Cu复相陶瓷材料的电阻率随着铜含量的增加而下降,且在渗流阈值（x=25wt%）附近呈现非线性的下降趋势,复合材料从绝缘体逐渐变为导体.室温下1 kHz当Cu含量达到x=30wt%时复相陶瓷的介电常数为~9000,这是由于在导体和绝缘体的相界面处积累大量的空间电荷,并由此产生界面极化,导致介电常数的显著增大,且随着导体含量的增加,这种界面效应更加明显.复相陶瓷的介电损耗随着铜含量的增加而增大,但随着频率的升高,由于空间电荷的减少又会使损耗呈现下降的趋势.在25~115℃的温度范围内,复相陶瓷温度系数小于5%,具有很高的介电常数温度稳定性.The BaTiO3/Cu composite ceramics doped with Cu in the content range of 0-30 wt% were prepared by the solid-state reaction.The microstructure,percolation threshold and dielectric properties of ceramics were inves-tigated.The results show that the resistivity of BaTiO3/Cu composite ceramic increases with Cu content decreasing and the relationship between them has a non-linear downward trend at the percolation threshold（x=25wt%）,then the composite is gradually changing from insulator into conductor.The value of εr of BaTiO3/Cu composites is raised with the increase of Cu content,and the maximal value is about 9000 at 1 kHz at room temperature as Cu content of 30wt%.The dielectric loss of BaTiO3/Cu composites increases with the increasing Cu doping,but then decreased with the increasing frequency,which is due to the reducing of the amount of space charge.The tempera-ture coefficient is less than 5% in the temperature range from 25℃ to 115℃,and the dielectric constant is provided with high temperature stability.

关 键 词：BaTiO3/Cu复相陶瓷 渗流理论 介电性能 

分 类 号：TB321[一般工业技术—材料科学与工程]