锰基反铁磁外延薄膜中拓扑霍尔效应

最近，反铁磁自旋电子学作为一个新的研究热点备受关注。已有的理论研究表明，Mn3X (X=Pt, Ir, Rh, Ge, Sn, Ga等)非共线反铁磁材料中存在可观的拓扑霍尔电导率，但是缺乏相应的实验研究。本项目拟对L12 IrMn3和PtMn3有序合金外延薄膜，以及FeMn、IrMn、PtMn无序合金外延薄膜中拓扑霍尔效应进行研究。首先，借助于磁控溅射和脉冲激光沉积技术，摸索优化上述外延薄膜的生长工艺条件。在此基础上，通过改变薄膜厚度以及变温测量研究拓扑霍尔效应电阻率与纵向电阻率之间的标度关系。最后结合第一性原理计算，深刻揭示拓扑霍尔效应的电子态物理本质。

Very recently, antiferromagnetic spintronics has attracted much attention, as a newly emerging research field. Theoretical studies have extensively shown that Mn3X (X=Pt, Ir, Rh, Ge, Sn, Ga) ordered alloys exhibit large anomalous Hall effect, i.e., topological Hall effect, due to their non-collinear spin structure. In contrast, experimental studies still lack. Accordingly, we will focus on topological Hall effect of L12 ordered IrMn3 and PtMn3 epitaxial films and disordered FeMn, IrMn, PtMn ones. Firstly, we will explore and optimize the fabrication condition of L12 ordered IrMn3 and PtMn3 epitaxial films and disordered FeMn, IrMn, PtMn ones, with the magnetron sputtering and pulse laser deposition techniques. Secondly, we will study the scaling law of the topological Hall effect in these films, by varying the measurement temperature and the film thickness. Finally, ab. initio calculation will also be made in order to deeply understand the physics mechanism of the topological Hall effect from the view point of the electronic band structure near the Fermi level.