论文标题
QUASI-TWO维平面磁铁SR（CO $ _ {1-X} $ ni $ _X $）$ _ 2 $ AS $ _2 $中的磁性顺序和波动
Magnetic order and fluctuations in quasi-two-dimensional planar magnet Sr(Co$_{1-x}$Ni$_x$)$_2$As$_2$
论文作者
论文摘要
我们使用中子散射来调查Sr（Co $ _ {1-x} $ ni $ _ {X}）_ 2 $ AS $ _2 $中的自旋激发，该_2 $ as $ _2 $，具有$ c $ - 轴不兑换的螺旋螺旋结构的二维（2d）内面积（2d）frane ferromagnetic（2d）ferromagnetic（fm）订单$ 0.25 $ 0.25 $ 0.25 $ 0.25;通过比较螺旋顺序的Sr（co $ _ {0.9} $ ni $ _ {0.1} $）$ _ 2 $ as $ _2 $和proamagnetic srco $ _2 $ as $ _2 $ AS $ _2 $的波向量和依赖能量的旋转激发（Co $ _ {0.9} $ ni $ _ {0.1} $） sr（co $ _ {1-x} $ ni $ _ {x}）_ 2 $ as $ _2 $，增强Quasi-2d FM自旋波动。但是，我们在密度功能理论和动态平均场理论（DFT+DMFT）中的频带结构计算未能生成从嵌套费米表面观察到的螺旋顺序的正确不相称的波矢量。由于传输测量结果表明，随着Ni兴奋剂和相关的晶格障碍的增加，平面内和$ C $轴的电阻率增加，我们得出的结论是，Sr（Co $ _ {1-x} $ ni $ _ {x} $ _ {x}）中的螺旋磁顺序是$ _2 $，因为$ _2 $可以通过量子订购机制来构建电源机械， Ruderman-Kittel-Kasuya-Yosida（rkky）相互作用。
We use neutron scattering to investigate spin excitations in Sr(Co$_{1-x}$Ni$_{x})_2$As$_2$, which has a $c$-axis incommensurate helical structure of the two-dimensional (2D) in-plane ferromagnetic (FM) ordered layers for $0.013\leq x \leq 0.25$. By comparing the wave vector and energy dependent spin excitations in helical ordered Sr(Co$_{0.9}$Ni$_{0.1}$)$_2$As$_2$ and paramagnetic SrCo$_2$As$_2$, we find that Ni-doping, while increasing lattice disorder in Sr(Co$_{1-x}$Ni$_{x})_2$As$_2$, enhances quasi-2D FM spin fluctuations. However, our band structure calculations within the combined density functional theory and dynamic mean field theory (DFT+DMFT) failed to generate a correct incommensurate wave vector for the observed helical order from nested Fermi surfaces. Since transport measurements reveal increased in-plane and $c$-axis electrical resistivity with increasing Ni-doping and associated lattice disorder, we conclude that the helical magnetic order in Sr(Co$_{1-x}$Ni$_{x})_2$As$_2$ may arise from a quantum order-by-disorder mechanism through the itinerant electron mediated Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions.
