高温超导转变温度电输运测量的影响因素研究  

A investigation of high temperature superconductor transition temperature and influencing factors

作　　者：王三胜[1,2] 宁晓帅[3] 贾明顺[1] 李华[1] 褚向华[3] 

机构地区：[1]北京航空航天大学物理学院,北京100091 [2]北京鼎臣超导科技有限公司,北京102206 [3]北京航空航天大学仪器科学与光电工程学院,北京100091

出　　处：《低温与超导》2012年第8期1-6,共6页Cryogenics and Superconductivity

基　　金：国家863项目(2009AA03Z207);国家自然科学基金项目(50602027;61171003);北京市自然科学基金项目(1102024);北京市科技新星(2008A020)等项目的部分资金支持

摘　　要：介绍了一种基于小型制冷机的高温超导转变温度测量装置,并且探究了在这套装置基础上进行实验所需要的测试条件。实验包括三项内容:(1)比较了电流换向法、三点Delta法以及偏置欧姆法三种消除热电势的方法,并最终决定采用适合本装置的电流换向法进行测量;(2)对通入样品的测试电流大小对测试的影响进行了研究,进而确定了进行高温超导材料转变温度测试时所通入电流的范围;(3)对钇系和铊系两种高温铜氧化物超导体进行反复测量,确定最大重复性误差小于0.4K。In this article, we described a device for measuring high - Tc superconducting transition temperature in a small cryocooler and a series of experiments was carried out to explore the best measurement conditions. Firstly, we used the current - reversal method, delta method, and offset - compensated ohms method by controlling the current flow and direction to reduce the thermovoltage effect. Secondly, we changed the current amplitude continually from 0.01 mA to 50mA to get the appropriate exci- tation current. And then, we compared the transition curve of the Y - based and the T1 - based superconductors by repeated measurements to determine the superconducting transition curve and critical temperature accurately. For the measurement system, the maximum repeated measurement error is less than 0.4K.

关 键 词：高温超导转变温度 低温制冷机 三点Delta法 钇系和铊系超导体 

分 类 号：TM26[一般工业技术—材料科学与工程]