Levchenko K, Prokscha T, Sadowski J, Radelytskyi I, Jakiela R, Trzyna M, Andrearczyk T, Figielski T, Wosinski T
Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668, Warsaw, Poland.
Paul Scherrer Institute, Laboratory for Muon Spin Spectroscopy, CH-5232, Villigen, Switzerland.
Sci Rep. 2019 Mar 4;9(1):3394. doi: 10.1038/s41598-019-40309-y.
Ferromagnetic semiconductor thin layers of the quaternary (Ga,Mn)(Bi,As) and reference, ternary (Ga,Mn)As compounds, epitaxially grown under either compressive or tensile strain, have been characterized from a perspective of structural and magnetization homogeneity. The quality and composition of the layers have been confirmed by secondary-ion mass spectrometry (SIMS). A thorough evaluation of the magnetic properties as a function of temperature and applied magnetic field has been performed by means of SQUID magnetometry and low-energy muon spin relaxation (µSR) spectroscopy, which enables studying local (on the nanometer scale) magnetic properties of the layers. The results testify that the ferromagnetic order builds up almost homogeneously below the Curie temperature in the full volume fraction of both the (Ga,Mn)As and (Ga,Mn)(Bi,As) layers. Incorporation of a small amount of heavy Bi atoms into (Ga,Mn)As, which distinctly enhances the strength of spin-orbit coupling in the quaternary (Ga,Mn)(Bi,As) layers, does not deteriorate noticeably their magnetic properties.
对在压缩应变或拉伸应变下外延生长的四元（Ga,Mn）（Bi,As）铁磁半导体薄层以及参考三元（Ga,Mn）As化合物，从结构和磁化均匀性的角度进行了表征。通过二次离子质谱（SIMS）确认了这些层的质量和成分。借助超导量子干涉仪磁力测量法和低能μ子自旋弛豫（µSR）光谱对作为温度和外加磁场函数的磁性能进行了全面评估，这使得能够研究这些层的局部（纳米尺度）磁性能。结果表明，在（Ga,Mn）As和（Ga,Mn）（Bi,As）层的整个体积分数中，铁磁序在居里温度以下几乎均匀地形成。将少量重Bi原子掺入（Ga,Mn）As中，这显著增强了四元（Ga,Mn）（Bi,As）层中自旋 - 轨道耦合的强度，但并未明显恶化其磁性能。
