铁磁/有机/绝缘/铁磁多层膜的隧道磁电阻研究

Study of tunneling magnetoresistance of ferromagnet/organic/insulator/ferromagnet magnetic tunneling junction

基于Slonczewski的自由电子近似理论,利用转移矩阵的方法计算了铁磁层/有机层/绝缘层/铁磁层磁性多层结构的隧穿磁电阻(tunneling magnetic resistance,TMR).保持有机层的厚度以及绝缘层的势垒高度不变,分别计算了在同一个有机层势垒高度且不同的自旋过滤因子β下的TMR随绝缘层厚度的变化;同时,还研究了在有机层和绝缘层的厚度不变,不同的β下,TMR随有机层势垒U的变化.结果表明,选取适当的β和绝缘层厚度能够获得大的TMR值;TMR随有机层势垒U的增加而增大.我们的计算结果对有机自旋注入、输运以及设计新的有机自旋电子器件的研究有一定的指导意义.

Based on the ferromagnetic/polymer/insulator/ferromagnetic （FM/O/I/FM） multilayered structures, we calculated the tunneling magnetic resistance （TMR） of such structure with the variation of the thickness of organic layer in the case of higher and lower spin filter factor for the organic layer by using the free electron model of Slonczewski. Also, the influence of the insulator layer thickness on TMR was calcu- lated. The large TMR could be achieved by choosing moderate spin filter factor and insulator layer thickness. It was also found that TMR increases with the increase of potential in organic layer. These calculated results will be possibly helpful in the organic spin injection, transport, detection and designing the new organic spintronic device.