基于小型低温制冷机的高温超导材料超导转变温度测量装置

高温超导材料的超导转变温度是判断超导材料性能优劣的一个重要指标,而超导材料转变温度的测量一般采用输运方法进行电阻随温度变化来确定.本文介绍一种新近研制的基于低温制冷机的高温超导材料超导转变温度测量装置,能有效的将样品温度从室温连续均匀的降至35K,通过Lab VIEW编写的数据采集系统人机界面,采用电流换向技术消除热电势,可以准确测量出超导材料的超导转变温度.经实验验证,该测量装置测量精确和重复性良好,可作为有效判定高温超导材料性能优劣的一种手段.

A SETUP FOR MEASURING SUPERCONDUCTING TRANSITION TEMPERATURE OF HIGH Tc SUPERCONDUCTOR BASED ON SMALL CRYOCOOLER

The superconducting transition temperature of High Tc superconductor is an important indicator to judge whether the superconducting sample is good or not.Usually,this measurement can be completed by measuring the resistance variation versus the temperature by transport current method.In this paper,one setup for measuring the superconducting transition temperature based on cryocooler is introduced.In our home made system,the sample’s temperature can be continuously cooled down from room temperature to 35K smoothly.By periodically reversing the direct current using four-probe measurement method,we try to eliminate the thermoelectric potential in order to obtain the sample resistance accurately.In the datum acquisition system,the human-machine interface is programmed by commercially available Lab VIEW system.After a series of experiments,we conclude that the precision and repeatability of the measuring setup is good,and it can be used as an effective way to measure the superconducting transition temperature,then judging the quality of superconductor materials.