论文标题
通过4D和5D掺杂在B20化合物中调节天空
Tuning skyrmions in B20 compounds by 4d and 5d doping
论文作者
论文摘要
这里报告了具有B20晶体结构的新型磁系统中的Skyrmion稳定，主要基于理论结果。重点是通过取代较重的4D和5D元素对合金对B20结构的3D sublattice的影响，并有雄心调整自旋轨道耦合及其对磁相互作用的影响。基于密度功能理论的最新方法用于计算各向同性和各向异性交换相互作用。据报道，5D掺杂的FESI和COSI的Dzyaloshinskii-Moriya相互作用的显着增强，并伴随着旋转刚度和螺旋化的大量修饰。微磁模拟与原子自旋动力学结合和从头开始磁相互作用揭示了所有这些系统的螺旋基态和野外诱导的天空。尤其是小型Skyrmions $ \ sim $ 50 nm的预计将以CO $ _ {0.75} $ OS $ _ {0.25} $ SI的价格为$ \ sim $ \ sim $ 148 nm，而Fe $ _ {0.75} $ {0.75} $ co $ _ {0.25} $ _ {0.25} $ si。凸壳分析表明，此处考虑的所有B20化合物在升高的温度下在结构上稳定，应该可以合成。通过粉末和单晶形式中讨论的RU掺杂的COSI系统的合成和结构分析，通过合成和结构分析在实验中证实了这一预测。
Skyrmion stabilization in novel magnetic systems with the B20 crystal structure is reported here, primarily based on theoretical results. The focus is on the effect of alloying on the 3d sublattice of the B20 structure by substitution of heavier 4d and 5d elements, with the ambition to tune the spin-orbit coupling and its influence on magnetic interactions. State-of-the-art methods based on density functional theory are used to calculate both isotropic and anisotropic exchange interactions. Significant enhancement of the Dzyaloshinskii-Moriya interaction is reported for 5d-doped FeSi and CoSi, accompanied by a large modification of the spin stiffness and spiralization. Micromagnetic simulations coupled to atomistic spin-dynamics and ab initio magnetic interactions reveal a helical ground state and field-induced skyrmions for all these systems. Especially small skyrmions $\sim$50 nm are predicted for Co$_{0.75}$Os$_{0.25}$Si, compared to $\sim$148 nm for Fe$_{0.75}$Co$_{0.25}$Si. Convex-hull analysis suggests that all B20 compounds considered here are structurally stable at elevated temperatures and should be possible to synthesize. This prediction is confirmed experimentally by synthesis and structural analysis of the Ru-doped CoSi systems discussed here, both in powder and in single-crystal forms.
