NM/FI/NI/FI/NM新型双自旋过滤隧道结的隧穿电导和隧穿磁电阻

在NM/FI/FI/NM型双自旋过滤隧道结(此处NM为非磁金属层，FI为铁磁绝缘体或半导体层)的基础上，我们提出一种NM/FI/NI/FI/NM新型双自旋过滤隧道结(此处NI表示非磁绝缘体或半导体层). 插入NI层的目的是为了避免原双自旋过滤隧道结中相邻FI层界面处磁的耦合作用所导致的对隧穿磁电阻的不利影响. 在自由电子近似的基础上，利用转移矩阵方法，对NM/FI/NI/FI/NM新型双自旋过滤隧道结的隧穿电导、隧穿磁电阻与FI层及NI层厚度的变化关系以及随偏压的变化关系进行了理论研究.计算结果表明，在NM/FI/NI/FI/NM新型双自旋过滤隧道结中仍可以得到很大的TMR值. 关键词： 双自旋过滤隧道结 隧穿磁电阻 非磁绝缘(半导)体间隔层

The tunnel conductance and tunnel magnetic resistance of NM/FI/NI/FI/NM double spin filter junction

Based on the NM/FI/FI/NM double spin filter junction (NM represents the nonmagnetic metal layer and FI the ferromagnetic insulator or semiconductor layer), a new type of double spin filter junction NM/FI/NI/FI/NM (NI represents the nonmagnetic insulator layer) is discussed. By inserting an nonmagnetic insulator layer between the ferromagnetic insulator layers, the adverse influence on the tunneling magnetic resistance (TMR) caused by the magnetic coupling at the interface between the ferromagnetic insulator (FI) layers can be avoided. Using the free-electron approximation and transfer matrix method the dependence of the tunneling conductance and TMR on the thickness of the FI layer and the NI layer and on the bias voltage in the double spin filter junction NM/FI/NI/FI/NM are studied.