低温下实验测量庞磁电阻材料的热导率  

THE THERMAL CONDUCTIVITY MEASUREMENT OF COLOSSAL MAGNETORESISTANCE MATERIAL AT LOW TEMPERATURES

作　　者：于帆[1] 薛坤[1] 孙继荣[2] 隋浩华[1] 

机构地区：[1]北京科技大学机械工程学院热科学与能源工程系,北京100083 [2]中国科学院物理研究所国家磁学重点实验室,北京100080

出　　处：《工程热物理学报》2010年第8期1351-1354,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50776009)

摘　　要：基于低频方波脉冲加热-冷却非稳态连续测量原理,应用PPMS多物性测量系统在温区150～360 K和外磁场0～9 T下对典型的庞磁电阻材料La（2/3）Ca（1/3）MnO3的热导率进行了实验研究。结果表明,在外磁场作用下庞磁材料在居里温度附近会发生明显的热导率增大（或热阻率减小）的磁致热阻现象,但磁热阻效应的程度在数值上要明显低于庞磁电阻效应。The thermal conductivity of a typical colossal magnetoresistance material La（2/3）Ca（1/3）MnO3 was measured in temperatures from 150 K to 360 K under different magnetic fields from 0 T to 9 T by using a physical property measurement system（PPMS）.The measurement principle is based on the unsteady continuous mode,and in the meantime the sample is heated and cooled by a series of low frequency square wave pulses.The experimental results show that the magneto-thermal resistance effect,namely the thermal conductivity increasing or the thermal resistivity decreasing with the magnetic field increasing,will take place near Curie temperature,but the magnitude of magneto-thermal resistance is obviously lower than the magnetoresistance.

关 键 词：热导率 磁致热阻效应 庞磁电阻材料 

分 类 号：O514[理学—低温物理]