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arXiv · 0811.3291

New S=1/2 Kagome Antiferromagnets A$_2$Cu$_3$SnF$_{12}$: A=Cs and Rb

T. Ono·K. Morita·M. Yano·H. Tanaka·K. Fujii·H. Uekusa·Y. Narumi·K. Kindo
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Abstract

We synthesized single crystals of the new hexagonal compounds A$_2$Cu$_3$SnF$_{12}$ with A=Cs and Rb, and investigated their magnetic properties. These compounds are composed of Kagomé layers of corner-sharing CuF$_6$-octahedra. Cs$_2$Cu$_3$SnF$_{12}$ has the proper Kagomé layer at room temperature, and undergoes structural phase transition at $T_\mathrm{t}\simeq 185$ K. The temperature dependence of the magnetic susceptibility in Cs$_2$Cu$_3$SnF$_{12}$ agrees well with the result of the numerical calculation for $S=1/2$ two-dimensional Heisenberg Kagomé antiferromagnet down to $T_\mathrm{t}$ with the nearest exchange interaction $J/k_\mathrm{B}\simeq 240$ K. Although the magnetic susceptibility deviates from the calculated result below $T<T_\mathrm{t}$, the rounded maxima were observed at approximately $T\simeq (1/6)J/k_\mathrm{B}$ as predicted by the theory. Cs$_2$Cu$_3$SnF$_{12}$ undergoes three-dimensional magnetic ordering at $T_\mathrm{N} = 20$ K.

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T. Ono, K. Morita, M. Yano, H. Tanaka, K. Fujii, H. Uekusa, Y. Narumi, K. Kindo. 2008-11-20. New S=1/2 Kagome Antiferromagnets A$_2$Cu$_3$SnF$_{12}$: A=Cs and Rb. https://doi.org/10.1088/1742-6596/145/1/012005

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