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arXiv 1902.01653cond-mat.str-el
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4d $^{4}$基($S=1$)蜂窝体系Ag $_{3}$ LiRu $_{2}$ O $_{6}$的非常规磁性

Unconventional magnetism in the 4d$^{4}$ based ($S=1$) honeycomb system Ag$_{3}$LiRu$_{2}$O$_{6}$

R. Kumar, Tusharkanti Dey, P. M. Ette, K. Ramesha, Atasi Chakraborty, I. Dasgupta, J. C. Orain, C. Baines, Sándor Tóth, A. Shahee, S. Kundu, M. Prinz-Zwick, A. … 展开作者

R. Kumar, Tusharkanti Dey, P. M. Ette, K. Ramesha, Atasi Chakraborty, I. Dasgupta, J. C. Orain, C. Baines, Sándor Tóth, A. Shahee, S. Kundu, M. Prinz-Zwick, A. A. Gippius, N. Büttgen, P. Gegenwart, A. V. Mahajan

摘要:

研究了Mott绝缘体系Ag $_{3}$ LiRu $_{2}$ O $_{6}$含Ru $^{4+}$(4 $d$ $^{4}$)的热力学和局域磁性.该材料以单斜$C2/m$结构结晶,其中RuO $_{6}$八面体形成边缘共享的二维蜂窝晶格,沿着$c$方向具有有限的堆叠顺序。大的负居里-外斯温度($θ_{CW}$ = -57 K)表明Ru $^{4+}$离子之间存在反铁磁相互作用,尽管磁化率和热容分别在1.8 K和0.4 K以下没有显示出磁性长程有序。$^{7}$ Li核磁共振(NMR)位移在120-300 K之间跟随体磁化率,并在120 K以下稳定。在0.2和2 K之间,随温度变化的自旋-晶格弛豫速率呈幂律行为,表明动态自旋相关与无带隙激发。电子结构的计算表明,$S = 1$描述的Ru-时刻和可能的重要性,进一步的邻居相互作用,也双二次和环交换条款,在确定的磁性。我们的$μ$ SR数据的分析表明,自旋冻结低于5 K,但自旋保持在静态和动态磁性之间的边界线,即使在20 mK。

英文摘要:

We have investigated the thermodynamic and local magnetic properties of the Mott insulating system Ag$_{3}$LiRu$_{2}$O$_{6}$ containing Ru$^{4+}$ (4$d$$^{4}$) for novel magnetism. The material crystallizes in a monoclinic $C2/m$ structure with RuO$_{6}$ octahedra forming an edge-shared two-dimensional honeycomb lattice with limited stacking order along the $c$-direction. The large negative Curie-Weiss temperature ($θ_{CW}$ = -57 K) suggests antiferromagnetic interactions among Ru$^{4+}$ ions though magnetic susceptibility and heat capacity show no indication of magnetic long-range order down to 1.8 K and 0.4 K, respectively. $^{7}$Li nuclear magnetic resonance (NMR) shift follows the bulk susceptibility between 120-300 K and levels off below 120 K. Together with a power-law behavior in the temperature dependent spin-lattice relaxation rate between 0.2 and 2 K, it suggest dynamic spin correlations with gapless excitations. Electronic structure calculations suggest an $S = 1$ description of the Ru-moments and the possible importance of further neighbour interactions as also bi-quadratic and ring-exchange terms in determining the magnetic properties. Analysis of our $μ$SR data indicates spin freezing below 5 K but the spins remain on the borderline between static and dynamic magnetism even at 20 mK.

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。

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