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=)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.
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 ntrn, 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.
出处
《应用科学学报》
CAS
CSCD
1997年第3期272-278,共7页
Journal of Applied Sciences
基金
国家自然科学基金