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arXiv · 1404.2033

Almost Perfect Frustration in the Dimer Magnet Ba$_2$CoSi$_2$O$_6$Cl$_2$

Hidekazu Tanaka·Nobuyuki Kurita·Makiko Okada·Eiji Kunihiro·Yutaka Shirata·Kotaro Fujii·Hidehiro Uekusa·Akira Matsuo·Koichi Kindo·Hiroyuki Nojiri
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Abstract

We determined the crystal structure of Ba$_2$CoSi$_2$O$_6$Cl$_2$, which was synthesized in this work, and investigated its quantum magnetic properties using single crystals. This compound should be described as a two-dimensionally coupled spin-1/2 XY-like spin dimer system. Ba$_2$CoSi$_2$O$_6$Cl$_2$ exhibits a stepwise magnetization process with a plateau at half of the saturation magnetization, irrespective of the field direction, although all the Co$^{2+}$ sites are equivalent. This indicates that spin triplets are localized owing to the almost perfect frustration of interdimer exchange interactions. Thus, the spin states for the zero and 1/2 magnetization-plateau states are almost exactly given by the simple product of singlet dimers and the alternate product of singlet and triplet dimers, respectively.

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Hidekazu Tanaka, Nobuyuki Kurita, Makiko Okada, Eiji Kunihiro, Yutaka Shirata, Kotaro Fujii, Hidehiro Uekusa, Akira Matsuo, Koichi Kindo, Hiroyuki Nojiri. 2014-04-08. Almost Perfect Frustration in the Dimer Magnet Ba$_2$CoSi$_2$O$_6$Cl$_2$. https://doi.org/10.7566/jpsj.83.103701

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