Cu_x(Al_2O_3)_(1-x)颗粒膜的巨霍耳效应研究  

Giant Hall Effect in Cu_x(Al_2O_3)_(1-x) Granular Films

作　　者：高俊[1] 蒋晓龙[1] 倪刚[1] 王飞[1] 张凤鸣[1] 都有为[1] 

机构地区：[1]南京大学固体微结构实验室,江苏南京210093

出　　处：《稀有金属》2003年第5期638-640,共3页Chinese Journal of Rare Metals

基　　金：国家重点基础研究发展规划项目的资助 (G19990 64 5 0 8)

摘　　要：在由磁性金属颗粒镶嵌在非磁金属或绝缘基体中而形成的两相非均匀颗粒系统中 ,当磁性金属的体积百分含量处于临界值时 ,体系的输运行为有许多奇异的现象。相继在在磁性金属 非磁金属和磁性金属 绝缘体系统中发现了巨磁电阻效应和隧道磁电阻效应 ;特别的在磁性金属 绝缘体系统中发现了反常霍耳效应的极大增强 ,称为巨霍耳效应。为了探讨颗粒体系的巨霍耳效应的机制 ,本文用离子束共溅射的方法制备了大约 1.5× 10 - 7m厚度的Cux(Al2 O3) 1 -x颗粒薄膜 ,研究了非磁金属 绝缘体体系 :Cu Al2 O3颗粒系统的巨霍耳效应 ,发现在量子渗流阈值时 ,霍耳电阻比正常金属高 2个数量级。When the volume fraction of the magnetic metal reaches the critical point in the ferromagnetic metal/non ferromagnetic metal system or ferromagnetic metal/insulator system, there are several novel properties happen. The giant magnetoresistance in ferromagnetic metal/non ferromagnetic metal and tunnelling magnetoresistance in magnetic metal/insulator system were found in these granular sysytem. Especially the extraordinary Hall effect with large enhancement were found in ferromagnetic metal/insulator system, and was termed as giant Hall effect. To study the mechanism of the giant Hall effect in granular system, the Cu x (Al 2O 3) 1- x granular film was fabricated using ion beam sputtering. The giant Hall effect in this system was studied. When the volume fraction of Cu reaches the quantum percolation, two orders′ enhancement of Hall effect is got ten.

关 键 词：霍耳效应 颗粒系统 Cux(Al2O3)1-x薄膜 

分 类 号：O482.51[理学—固体物理]