摘要
采用量子唯象模型研究金属颗粒膜巨磁电阻的特性．在计算散射截面时，考虑了颗粒内各杂质原子之间的相位相干性．依据实验报告提供的颗粒尺寸分布的数据，推导了巨磁电阻依赖于颗粒尺寸及其分布和外磁场的函数表示式．对样品ＦｅＡｇ的计算结果表明，其磁电阻随外磁场的变化和颗粒尺寸的分布有关；在某个颗粒尺寸标度Ｄ０，磁电阻出现极大值，尺寸标度Ｄ０的大小与外加磁场。
The magnetoresistance of magnetic granular alloys has been studied based on a quantum phenomenological model.We take into account the phase interference effectamong the impurity atoms in a grain to calculate the scattering cross section between conduction electron and atom.According to the size distribution data provided by the experiment reported,we have derived an expression for the magnetoresistance depending on the grain size,size distribution,and applied magnetic field.The calculated results for the Fe Ag sample have shown that the variation character of magnetoresistance with the external field depends on the size distribution of the grains.At a size scale D 0 ,the magnetoresistance shows a maximum value.The size scale D 0 depends on the applied field,the sample materials and fabrication conditions.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第9期1834-1840,共7页
Acta Physica Sinica
基金
国家自然科学基金
