Magnetic Behavior of Volborthite Cu_{3}V_{2}O_{7}(OH)_{2}·2H_{2}O Determined by Coupled Trimers Rather than Frustrated Chains.
Magnetic Behavior of Volborthite Cu_{3}V_{2}O_{7}(OH)_{2}·2H_{2}O Determined by Coupled Trimers Rather than Frustrated Chains.
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DOI：
10.1103/physrevlett.117.037206
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发表时间：
2015-09
影响因子：
8.6
通讯作者：
O. Janson;S. Furukawa;T. Momoi;P. Sindzingre;J. Richter;K. Held
中科院分区：
文献类型：
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作者：
O. Janson;S. Furukawa;T. Momoi;P. Sindzingre;J. Richter;K. Held
出于最近的实验表现出宽的1/3磁化平台的volborthite单晶，我们通过密度泛函理论（DFT）的单晶结构数据作为出发点进行微观建模。用DFT+U方法，我们发现了四种主要的磁交换：反铁磁交换J和J_{2}，铁磁交换J_{1}和J_{1}。模拟结果表明，所推导的自旋哈密顿量与实验低场磁化率和高场磁化强度数据吻合良好。1/3平台相属于由强J键形成的极化磁性三聚体。一个有效的J→∞模型显示出在平台相之前磁振子束缚态的凝聚趋势。
Motivated by recent experiments on volborthite single crystals showing a wide 1/3-magnetization plateau, we perform microscopic modeling by means of density functional theory (DFT) with the single-crystal structural data as a starting point. Using DFT+U, we find four leading magnetic exchanges: antiferromagnetic J and J_{2}, as well as ferromagnetic J^{'} and J_{1}. Simulations of the derived spin Hamiltonian show good agreement with the experimental low-field magnetic susceptibility and high-field magnetization data. The 1/3-plateau phase pertains to polarized magnetic trimers formed by strong J bonds. An effective J→∞ model shows a tendency towards condensation of magnon bound states preceding the plateau phase.