超低电阻率石墨/氧化铜/石墨三明治结构导电材料

Ultra-low-resistivity graphite/copper oxide/graphite sandwich conductive material

研制超低电阻率材料对于降低高速摩擦接触导电材料功耗以及推动室温超导材料的发展都具有十分重要的意义。本实验设计并制备了不同夹心层数、不同夹心层厚度和不同夹心层面积分数的石墨/氧化铜/石墨三明治结构(Graphite/Copper Oxide/Graphite Sandwich Structure,G/CO/G-SS)导电材料体系和样品。采用XRD、SDM和SEM表征样品的物相和形貌,利用LCR数字电桥测量样品电阻,并使用四探针测试仪进行标定。结果表明,粒径为10~20μm的氧化铜粉末均匀涂敷在石墨基体表面,恰好填补了石墨表面缺陷。G/CO/G-SS导电材料夹层厚度达到基本单元层厚度时具有9.09×10^(-10)Ω·m(远低于铜的电阻率)的超低电阻率,与石墨基体(8×10^(-6)Ω·m)相比,降低了约4个数量级。研究发现,以高电阻率的氧化铜粉体作为三明治结构的夹心层,在石墨/氧化铜界面上形成了高通导电网络,极大地提高了材料的电导率,并且G/CO/G-SS导电材料电阻率随着复相界面数的增加而降低。

The development of ultra-low resistivity materials is critical to reduce power consumption of high-speed frictional contact conductive materials and to realize superconductivity at room temperature.Here graphite/copper oxide/graphite sandwich(G/CO/G-SS)conductive material samples were prepared and designed with different sandwich layers,sandwich layer thicknesses,and sandwich layer area fractions.The phase and morphology of these samples were characterized using XRD,SDM,and SEM.The resistance of these samples was measured using an LCR digital bridge and calibrated using a four-probe tester.The results demonstrate that copper oxide powder with particle size from 10 to 20 micrometers is uniformly coated on the surface of the graphite paper.The coating fills the surface voids of the graphite substrate,resulting in a uniform material morphology.The conductive material layer,composed of G/CO/G-SS,has a thickness comparable to that of the substrate layer.The resistivity of the conductive material is 9.09×10^(-10)Ω·m,which is significantly lower than that of copper.Moreover,it represents a remarkable reduction of four orders of magnitude in resistivity compared to the resistivity of the graphite substrate,which is 8×10^(-6)Ω·m.It is found that the utilization of high-resistivity copper oxide powder as the interlayer of the structure can lead to the formation of a high conductive network at the graphite/copper oxide interface,thereby enhancing the conductivity of the material.Additionally,the resistivity of the G/CO/G-SS conductive material decreases with the increase of the contact interface number of the complex phase.