Structural and magnetic characterisations along with first-principles total energy calculations based on the density functional theory have been combined to investigate the effects of (001) and (111)-oriented Ge substrates on the formation of GeMn nanocolumns. The samples were grown by means of molecular beam epitaxy (MBE) at the growth temperature ( T S ) of 130 °C, the Mn concentration of ∼6% and the film thickness of ∼80 nm. We found that due to the surfactant effect of Mn atoms, Ge 0,94 Mn 0,06 films grown on the Ge(001) substrate exhibit the nanocolumn structure along the growth direction and the Curie temperature ( T C ) is higher than 400 K. On the other hand, for the Ge 0,94 Mn 0,06 films grown on the Ge(111) substrate, Mn adatoms can easily diffuse into deeper layers through the interstitial sites, resulting in the formation of Ge 3 Mn 5 streaks along the preferred...

中文翻译：

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深入了解高温GeMn纳米柱的形成：基底晶体取向对其结构和磁性的影响

结合结构和磁性特征以及基于密度泛函理论的第一性原理总能量计算，以研究（001）和（111）取向的Ge衬底对GeMn纳米柱形成的影响。样品通过分子束外延（MBE）在130°C的生长温度（TS）上生长，Mn浓度约为6％，膜厚度约为80 nm。我们发现，由于Mn原子的表面活性剂作用，在Ge（001）衬底上生长的Ge 0,94 Mn 0,06膜沿生长方向显示出纳米柱结构，居里温度（TC）高于400 K.另一方面，对于在Ge（111）衬底上生长的Ge 0,94 Mn 0,06膜，Mn原子很容易通过间隙位置扩散到更深的层中，