MgO基垂直磁各向异性隧道结的电子输运研究

项目名称： MgO基垂直磁各向异性隧道结的电子输运研究

项目编号： No.11274094

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 贾兴涛

作者单位： 河南理工大学

项目金额： 75万元

中文摘要： 铁磁性过渡金属(FM)在MgO表面诱导产生的垂直磁各向异性(PMA)，已经证明可以使FM/MgO/FM隧道结(MTJs)具有更低的驱动磁化翻转的临界电流(Jc)和更小的功能单元体积，在基于自旋转矩(STT)效应的随机存储(STT-RAM)领域展现出光明的应用前景。因此，具有PMA性质的MgO基MTJs的磁电阻(MR)和STT成为目前自旋电子学的研究热点。基于第一性原理方法，项目拟研究FM层厚度、FM层的非对称性、FM/MgO界面无序、贵金属插层和不同FM（Fe、Co、CoFe和CoFeB）对MgO基MTJs的PMA性质以及MR和STT的影响。从理论上理解具有PMA性质的MgO基MTJs的MR和STT等基础问题。此外，项目还拟研究该体系的温度效应（热电效应和温差产生的STT）。研究成果将为STT-RAM跨越最后障碍(即保持热稳定下使Jc降低到~10^5A/cm^2)走向应用奠定一定基础。

中文关键词： MgO基磁性隧道结；自旋转矩；自旋赛贝克效应；反铁磁；自旋动力学

英文摘要： Interface induced perpendicular magnetic anisotropy (PMA) have demonstrated merit to lower critical current (Jc) for magnetization switching and to decrease unit volume in ferromagnet/MgO/ferromagnet (FM/MgO/FM) magnetic tunnel junctions (MTJs), which shows perspective in spintronic memories application based on spin transfer torque (STT) effect named STT-RAM. As a result, the fundamental physics of electronic transport, such as magnetoresistance (MR) and STT, in MgO based MTJs with PMA has become one of hot issues in spintronics. Based on parameter-free first-principle calculations, the project focus on the MR and STT in MgO based MTJs with PMA as function of thickness of FM, asymettry of FM, disorder at FM/MgO interface, noble metal insertion, and FM materials (Fe, Co, CoFe, and CoFeB alloy). We try to give a theoretical understand of the fundamental physics of electronic transport in MgO based MTJs with PMA.Moreover, we try to study the thermal effect in MgO based MTJs with PMA, such as thermalpower effect and thermal STT. The result of the project would be fundamental for the commercial application of STT-RAM by lowing the Jc to ~10^5A/cm^2 while maintaining thermal stability.

英文关键词： MgO-based magnetic tunnel junction；spin transfer torque；spin Seebeck coefficient；antiferromagnet；spin dynamics