低温强磁场电子输运特性自动测试系统

Automatic Hall Measurement System for Electron Transport at Low Temperature and High Magnetic Field

本文介绍一套性能优良,功能完备的低温强磁场下电子输运特性的自动测试系统。该系统由IBM—PC微机,Solartron F081高精度数字电表,702控温仪,及自行研制的64通道独立开关信号源,测试转找线路,自制高精度恒流源,超导磁体及电源,低温恒温器组成,系统通过微机对温度、样品电流及磁场进行自动设置或扫描,同时对二块样品进行霍耳电压和磁阻电压测量、运算、作图,以得到所需的物理参数及曲线。本文还叙述如何采用低热电势机械开关消除系统感生与感应电势,使系统多路直流测试精度达2μV,以及采用动态信号测试技术实现测试实时性及提高测试效率。

An automatic Hall measurement system for electron transport at low tem-peratures and high magnetic fields has been established.The system consists of an IBM—PCcomputer,a 7081 precision voltmeter,a multi-channel digital signal,a universal switch board,a702 temperature controller,a precision current signal and the superconducting cryomagnet and its power.The temperature,the sample current and the magneticfield can be set or swpt by the control of the computer while the Hall voltage and resistance voltage are collected,calculated and drawn to obtain various physical constants and figures.The sys-tem can provide a DC voltage precision of 2μV on the sample condition of temperatures 1.2K—300K,currents 1μA—1A and magnetic fields 0—12T.