钙钛矿La $_{1-x}$ Ba $_{x}$ CoO $_{3}$中结构驱动的自旋翻转跃迁与绝缘体-金属跃迁的可能联系
Possible link of a structurally driven spin flip transition and the insulator-metal transition in the perovskite La$_{1-x}$Ba$_{x}$CoO$_{3}$
摘要：
用中子散射方法研究了La $_{1-x}$ A $_{x}$ CoO $_{3}$（A = Ca，Sr，Ba）中磁基态的复杂性质.先前观察到，铁磁（FM）以及反铁磁（AFM）的相关性可以共存之前的绝缘体-金属转变（IMT）。我们关注Ba相图中的一个独特区域，从x = 0.17 - 0.22，在该区域中，首先出现一个相称的AFM相，其传播矢量k =（0，-0.5，0.5），并且Co矩在菱形晶格的（001）$_{R}$平面中。随着x的增加，AFM分量减弱，同时出现FM阶，FM Co矩沿（001）$_{R}$（=（111）$_{C}$）轴定向。当x = 0.22时，随着晶体完全转变为正交（Pnma）结构，出现到新FM分量的自旋翻转，其中Co矩指向新方向，（001）$_{O}$（=（110）$_{C}$）。正是磁Pnma相的出现导致了IMT。
英文摘要：
The complex nature of the magnetic ground state in La$_{1-x}$A$_{x}$CoO$_{3}$ (A = Ca, Sr, Ba) has been investigated via neutron scattering. It was previously observed that ferromagnetic (FM) as well as antiferromagnetic (AFM) correlations can coexist prior to the insulator-metal transition (IMT). We focused on a unique region in the Ba phase diagram, from x = 0.17 - 0.22, in which a commensurate AFM phase appears first with a propagation vector, k = (0, -0.5, 0.5), and the Co moment in the (001)$_{R}$ plane of the rhombohedral lattice. With increasing x, the AFM component weakens while an FM order appears with the FM Co moment directed along the (001)$_{R}$ (=(111)$_{C}$) axis. By x = 0.22, a spin flip to new FM component appears as the crystal fully transforms to an orthorhombic (Pnma) structure, with the Co moments pointing along a new direction, (001)$_{O}$ (=(110)$_{C}$). It is the emergence of the magnetic Pnma phase that leads to IMT.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
