利用金属垫片做为电极在金刚石对顶砧上精确测量样品电导率的研究  

Accurate electrical conductivity measurement in diamond anvil cell with the metal gasket as electrode

作　　者：彭刚[1] 韩永昊[1] 刘才龙[1] 吴宝嘉[1,2] 胡廷静[1] 崔晓岩[1] 刘鲍[1] 王月[1] 李冬妹[1] 刘洪武[1] 高春晓[1] 马博明[3] 马艳章[3] 

机构地区：[1]吉林大学超硬材料国家重点实验室,长春130012 [2]延边大学理学院物理系,延吉133002 [3]美国德克萨斯理工大学,德克萨斯州79409

出　　处：《原子与分子物理学报》2009年第4期757-760,共4页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10874053;50532020);科技部973课题(2005CB724404);教育部创新团队(IRT0625)

摘　　要：利用传统的四电极方法在金刚石对顶砧(DAC)上进行原住的样品电导率测量时,如果金属垫片样品孔内壁不能完全绝缘,测量结果将会存在很大的误差.为避免该实验误差的产生,作者提出了用双电极模型进行电导率测量的方法,即在DAC砧面上制备一个圆形测量电极的同时,将金属垫片样品孔的内壁做为第二个测量电极,并利用有限差分方法对电导率进行计算.通过这种方式,由金属垫片不绝缘而产生很大测量误差的问题得以解决.实验结果表明测量相对误差被控制在7%以下.Incomplete insulation between the sample and the metal gasket could always generate unex- pected giant errors for in-situ conductivity measurement with a DAC by traditional four-electrode method. In order to avoid the failure caused by the electric short between the sample and the gasket, the authors took conductivity measurements with a two-electrode model and treated the inside wall of the gasket as one cylindrical detecting probe. By doing so, the electric short between the sample and the gasket was not a severe problem any more that brought large error or unexpected failure to the conductivity measurement with DAC. In the model the conductivities were computed by finite difference method and the relatiw errors were smaller than 7%.

关 键 词：电导率 金刚石对顶砧 电极 相对误差 有限差分 

分 类 号：O521.3[理学—高压高温物理] O411.3[理学—物理]