铁磁隧道结的隧穿磁电阻研究

Study of Tunneling Magnetoresistance in Ferromagnetic Tunnel Junctions

在Slonczewsik自由电子理论模型下,研究了一由铁磁/铁磁绝缘体/铁磁构成的隧道结在零偏压下的隧穿电导、自旋极化率和隧穿磁阻比率。结果表明,隧道结的磁结构对TC(隧穿电导)和TMR(隧穿磁阻)的值有很大的影响,在两磁极磁化方向相同且与势垒分子场同向时,TC取到最小值,而方向为反平行时,TC数值为最大,同时还对分子场取向对自旋电子输运性质的影响进行了分析,所得结果对自旋器件的设计有一定意义。

For a magnetic tunneling junction with ferromagnetic metal/magnetic potential barrier layer/ferromagnetic metal structure,tunneling conductance,spin polarization and tunneling magneto resistance rate under zero bias voltage are calculated in a quasi-free electron model.The results show that TC and TMR strongly depend on the magnetization configuration of the junction.The TC reaches its maximums when the magnetic moments of the two electrodes are parallel to each other but antiparallel to that of the barrier,whereas the minimums appear when the magnetic moments of both electrodes and the barrier are parallel.The impact of molecular field orientation on tunneling of electrons is analyzed.It exhibits useful instructions for the design of spin electronic devices.