在金属烧绿石Nd $_2$ Mo $_2$ O $_7$中,导电钼子晶格采用倾斜但几乎共线的铁磁有序,具有非零标量自旋手征。化学势可以通过用Ca $^{2+}$取代Nd $^{3+}$来控制,同时仅向导电状态引入最小的额外无序。在这里,我们证明了倾斜的铁磁状态的稳定性,包括钼自旋的倾斜角,在(Nd $_{1-x}$ Ca $_{x}$)$_2$ Mo $_2$ O $_7$(NCMO)与$x\le 0.15$使用磁化率测量。Mo-Mo和Mo-Nd磁耦合在$x=0.22$以上都改变了符号,在那里倾斜的铁磁态让位于自旋玻璃金属区。系统地分离了两种磁性亚晶格对居里-外斯定律的贡献。
英文摘要:
In the metallic pyrochlore Nd$_2$Mo$_2$O$_7$, the conducting Molybdenum sublattice adopts canted, yet nearly collinear ferromagnetic order with nonzero scalar spin chirality. The chemical potential may be controlled by replacing Nd$^{3+}$ with Ca$^{2+}$, while introducing only minimal additional disorder to the conducting states. Here, we demonstrate the stability of the canted ferromagnetic state, including the tilting angle of Molybdenum spins, in (Nd$_{1-x}$Ca$_{x}$)$_2$Mo$_2$O$_7$ (NCMO) with $x\le 0.15$ using magnetic susceptibility measurements. Mo-Mo and Mo-Nd magnetic couplings both change sign above $x=0.22$, where the canted ferromagnetic state gives way to a spin-glass metallic region. Contributions to the Curie-Weiss law from two magnetic sublattices are separated systematically.
Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所,北京凝聚态物理国家实验室);University of Chinese Academy of Sciences(中国科学院大学);Condensed Matter Physics Data Center, Chinese Academy of Sciences(中国科学院凝聚态物理数据中心)
Evolution of structure and magnetism across the metal-insulator transition in the pyrochlore iridate $($Nd$_{1-x}$Ca$_x)_2$Ir$_2$O$_7$
我们报告的演化的热金属绝缘体转变的多晶样品的Nd $_2$ Ir $_2$ O $_7$空穴掺杂后,通过取代Nd $^{3+}$的Ca $^{2+}$。Ca取代介导的填充控制莫特样过渡,最小的可分辨的结构变化,而不改变网站的对称性。局部结构证实,Ca取代不会导致局部化学相分离,吸收光谱确定,Ir阳离子保持自旋轨道纠缠的电子配置。的金属-绝缘体的转变与反铁磁有序的Ir亚晶格上的所有测量的样品相一致,都降低了起始温度与Ca含量。弱低温上升的磁化率和电阻率的样品与高钙含量表明,钕亚晶格反铁磁性继续耦合到金属制度的载体。
Magnetism in antiperovskite (Li$_2$\textit{M})\textit{Ch}O (\textit{M} = Fe, Mn, Co; \textit{Ch} = S, Se) diluted magnets with fixed 1/3 filling: the key role of magnetic anisotropy
Kirchhoff Institute for Physics, Heidelberg University(海德堡大学基尔霍夫物理研究所);Leibniz Institute for Solid State and Materials Research Dresden(德累斯顿莱布尼兹固体与材料研究所);Department of Physics, Faculty of Science, Sohag University(索哈格大学理学院物理系)
Magnetism and $T-x$ phase diagrams of Na and Ag substituted EuCd$_2$As$_2$
EuCd $_2$ As $_2$是一种反铁磁半金属,根据其磁性状态和激发态,可以具有非平凡的拓扑性质。在这里,我们报道了Eu(Cd $_{1-x}$ Ag $_x$)$_2$ As $_2$和Eu $_{1-y}$ Na $_y$ Cd $_2$ As $_2$的合成和表征,并研究了掺杂后磁序的演变和性质。温度取代相图构造的电阻和磁化率数据。我们观察到分裂的磁性转变成两个不同的过渡,并逐渐增加的过渡温度与Ag和Na取代。另一个过渡或多或少与掺杂无关。我们进一步表明,一个净铁磁矩的磁性状态是稳定的Ag和Na掺杂,这可以解释考虑由于取代的能带填充的变化,建议由密度泛函理论(DFT)计算。因此,我们表明,化学取代和随后的能带填充的变化可能是一种途径,以调整磁基态和稳定的铁磁相EuCd $_2$作为$_2$。
Structural stability, electronic structure, and magnetism of the $d^9$ double infinite-layer La$_3$Ni$_2$O$_5$F under chemical pressure and epitaxial strain
Persistent Interfacial Topological Hall Effect Demonstrating Electrical Readout of Topological Spin Structures in Insulators
University of Nebraska, Lincoln(内布拉斯加大学林肯分校);Fudan University(复旦大学);North Carolina State University(北卡罗来纳州立大学);Georgia Institute of Technology(佐治亚理工学院);Bryn Mawr College(布林茅尔学院);Argonne National Laboratory(阿贡国家实验室)