小磁性颗粒膜和大磁性颗粒膜的巨磁电阻

应用科学学报 ›› 1997, Vol. 15 ›› Issue (3): 272-278.

小磁性颗粒膜和大磁性颗粒膜的巨磁电阻

唐多强, 杨新娥, 张代钟

天津大学

收稿日期:1995-09-19 修回日期:1996-04-04 出版日期:1997-09-30 发布日期:1997-09-30
作者简介:唐多强:副教授,天津大学应用物理系,天津 300072
基金资助:
国家自然科学基金

GIANT MAGNETORESISTANCES OF MAGNETIC GRANULAR FILMS WITH SMALL AND LARGE GRAINS

TANG DUOQIANG, YANG XINE, ZHANG DAIZHONG

Department of Applied Physics, Tianjin University, Tianjin 300072

Received:1995-09-19 Revised:1996-04-04 Online:1997-09-30 Published:1997-09-30

摘要/Abstract

摘要： 该文用玻恩(Born)近似方法计算了大磁性颗粒(颗粒包含原子数n>>12)和小磁性颗粒(n<12)薄膜中传导电子与颗粒的散射截面,并推导出在外磁场作用下两种磁颗粒膜的巨磁电阻公式.结果表明,小颗粒膜磁电阻的数值随颗粒包含原子数增加而变大,当颗粒尺寸增大达到某个长度标度L₀(n₀=8L₀³/a₀³)时,磁电阻有极大值;巨磁电阻随着颗粒表面粗糙度的增加而增大,并来源于传导电子和磁性颗粒之间的与自旋有关的散射势的贡献;本模型计算结果与已有的实验符合.

关键词: 巨磁电阻, 磁性颗粒膜

Abstract: We have calculated the scattering cross sections of the magnetic granular films with small grains, each of which contains atom number n<12, and large grains (n>>12) by Born approximation. Besides, we derived the formulas of the giant magne-toresistances(GMR) of the films. The results show that for small grains the GMRincreases with the atom number n. At a scale n₀, the GMR has the maximum value. For n>n₀, GNR decreases with the number n. The results also show that GMR increases dis-tinctly with the roughness of the surface of the grains and it comes from the spin-depen-dent scattering between conduction electrons and magnetic grains. With our model, the calculation results are in agreement with the experiments reported.

Key words: giant magnetoresistance, magnetic granular film

唐多强, 杨新娥, 张代钟. 小磁性颗粒膜和大磁性颗粒膜的巨磁电阻[J]. 应用科学学报, 1997, 15(3): 272-278.

TANG DUOQIANG, YANG XINE, ZHANG DAIZHONG. GIANT MAGNETORESISTANCES OF MAGNETIC GRANULAR FILMS WITH SMALL AND LARGE GRAINS[J]. Journal of Applied Sciences, 1997, 15(3): 272-278.