Magnetic exchange couplings in the single-molecule magnet of Mn(12)-Ac.
Magnetic exchange couplings in the single-molecule magnet of Mn(12)-Ac.
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DOI：
10.1063/1.2905217
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发表时间：
2008-04
期刊：
影响因子：
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通讯作者：
Jun-rong Zhang;Lunhua He;H. Cao;Fangwei Wang;Pan-lin Zhang
中科院分区：
文献类型：
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作者：
Jun-rong Zhang;Lunhua He;H. Cao;Fangwei Wang;Pan-lin Zhang
用经典的MonteCarlo方法模拟了Mn（12）-Ac的四种各向同性交换作用。在10 ~ 100 K温度范围内，平衡磁化率得到了很好的再现。在0.1 K下计算的有效自旋与基态自旋一致。结果表明，J（1）和J（2）是强反铁磁的，但J（2）的大小远小于J（1）的大小。J（3）和J（4）都有利于弱反铁磁耦合。研究了交换耦合对磁性和基态自旋的影响。100 K以下的磁化率更多地取决于J（2）而不是更强的J（1）。弱交换耦合J（3）和J（4）对基态组态有显著的阻挫效应。
Four types of isotropic exchange interactions of Mn(12)-Ac are obtained by using the classical Monte Carlo simulations. The equilibrium susceptibilities are well reproduced in the temperature range between 10 and 100 K. The calculated effective spin at 0.1 K coincides with the ground-state spin. Our results show that J(1) and J(2) are strong antiferromagnetic, but the magnitude of J(2) is much smaller than that of J(1). Both J(3) and J(4) favor weakly antiferromagnetic couplings. The effects of the exchange couplings on the magnetic properties and ground-state spin are investigated too. The magnetic susceptibilities below 100 K depend more on J(2) rather than on the stronger J(1). The weak exchange couplings J(3) and J(4) have significant frustration effects on the ground-state configuration.