顶端加载、温度范围在300~1.4K的多功能交流测量恒温器  

A 300-1.4K TOP-LOADING^4 He CRYOSTAT FOR MULTI-PUROSE AC MEASUREMENTS

作　　者：樊洁[1] 宋小会[2] 景秀年[2] 李山林[2] 张殿琳[2] 

机构地区：[1]西北大学现代物理研究所,西安710069 [2]中国科学院物理研究所,北京100080

出　　处：《低温物理学报》2005年第4期355-359,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金资助项目~~

摘　　要：本文介绍了一台用于交流小讯号测量的低温恒温器.利用内液池减压,最低温度可达1.370K,并且在测量功率为0.15mW时,内液池液氦可以维持样品温度在1.4K达20小时以上.系统装置了在8T的背景磁场内最高可达0.18T的交变调制场,从而可以实现利用双交流法精细测量磁阻或霍耳系数随磁场变化的函数关系.试验结果表明,此恒温器具有低液氦蒸发量和可从1.3~300K连续控温的特点.用此装置对Co膜的霍尔系数测量的实验中,霍尔电压变化量的测量精度达到了0.5nV.The present report describes a cryostat specially designed for multi-purpose ac measurements over the temperature range from ～1. 4K to 300K. Special efforts have been made for decreasing the heat leak from both room temperature and surrounding helium to the pumped helium which the sample holder is thermally contacted with. The sample can be kept at 1.4K for more than 20 hours with the measuring power of 0. 15roW. The combination of a modulation field of～0. 18T and a dc background field of 8T makes it possible to realize double-ac measurement of both magnetoresistance and Hall coefficient RH. A test experiment of the Hall coefficient of Co films shows that the measurement accuracy can be reached down to 0. 5nV.

关 键 词：低温恒温器 小讯号测量 双交流调制法 低温恒温器 交流测量 温度范围 多功能 加载 顶端 系统装置 磁场变化 最低温度 

分 类 号：TM933.13[电气工程—电力电子与电力传动]