摘要
基于Inoue模型,提出了一个修正理论来研究金属-绝缘体颗粒膜的隧穿磁电阻效应.假定颗粒膜中铁磁颗粒的尺寸服从对数正态函数,通过两个临界尺寸D1(T)和D2(T)将颗粒膜中的铁磁颗粒分为三类:超顺磁颗粒、单畴铁磁颗粒和多畴颗粒.同时引进一个参数k2来描述超顺磁颗粒与单畴铁磁颗粒对颗粒膜巨磁电阻效应影响的权重,另一个参数k1来描述基体对铁磁颗粒自旋极化率的影响.计算结果表明仅有单畴铁磁颗粒对颗粒膜的隧穿磁电阻效应起主导作用.
Based on the model of Inoue, a modified theory was presented to study the giant magnetoresistance of metal - insulator granular films. The size distribution of granules in granular films was assumed to satisfy the log - normal function and all granules were divided into superparamagnetic, single domain ferromagnetic and multidomain ferromagnetic granules. Meanwhile two parameters k1 and k2 were introduced to describe the effect of matrix characteristic on the spin polarization of ferromagnetic granules and the weight of single domain ferromagnetic granules relative to superparamagnetic ones with TMR, respectively. The calculated results indicated that only single domain ferromagnetic granules play a key role in giant magnetoresistance.
出处
《广西师范学院学报（自然科学版）》
2007年第4期47-52,共6页
Journal of Guangxi Teachers Education University(Natural Science Edition)
基金
山东省自然科学基金资助项目(Y2006A02
2005ZX11)
关键词
颗粒膜
隧穿磁电阻效应
对数-正态分布
自旋极化
granular film
tunnelling magnetoresistance effect
log - normal distribution
spin polarization
