Andrearczyk Tomasz, Sadowski Janusz, Wróbel Jerzy, Figielski Tadeusz, Wosinski Tadeusz
Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland.
Department of Physics and Electrical Engineering, Linnaeus University, SE-39182 Kalmar, Sweden.
Materials (Basel). 2021 Aug 10;14(16):4483. doi: 10.3390/ma14164483.
We have thoroughly investigated the planar Hall effect (PHE) in the epitaxial layers of the quaternary compound (Ga,Mn)(Bi,As). The addition of a small amount of heavy Bi atoms to the prototype dilute ferromagnetic semiconductor (Ga,Mn)As enhances significantly the spin-orbit coupling strength in its valence band, which essentially modifies certain magnetoelectric properties of the material. Our investigations demonstrate that an addition of just 1% Bi atomic fraction, substituting As atoms in the (Ga,Mn)As crystal lattice, causes an increase in the PHE magnitude by a factor of 2.5. Moreover, Bi incorporation into the layers strongly enhances their coercive fields and uniaxial magneto-crystalline anisotropy between the in-plane ⟨110⟩ crystallographic directions in the layers grown under a compressive misfit strain. The displayed two-state behaviour of the PHE resistivity at zero magnetic field, which may be tuned by the control of applied field orientation, could be useful for application in spintronic devices, such as nonvolatile memory elements.
我们已经深入研究了四元化合物(Ga,Mn)(Bi,As)外延层中的平面霍尔效应(PHE)。在原型稀磁半导体(Ga,Mn)As中添加少量重Bi原子，可显著增强其价带中的自旋轨道耦合强度，这从本质上改变了材料的某些磁电特性。我们的研究表明，在(Ga,Mn)As晶格中仅添加1%的Bi原子分数来替代As原子，会使平面霍尔效应的幅度增加2.5倍。此外，在压缩失配应变下生长的层中，Bi掺入层中会强烈增强其矫顽场以及面内<110>晶向之间的单轴磁晶各向异性。在零磁场下平面霍尔效应电阻率所显示的双态行为，可通过控制外加磁场方向进行调节，这对于自旋电子器件（如非易失性存储元件）的应用可能是有用的。
