Density functional study of the magnetic coupling in V(TCNE)2
Density functional study of the magnetic coupling in V(TCNE)2
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DOI：
10.1103/physrevb.79.085201
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发表时间：
2009-02-01
影响因子：
3.7
通讯作者：
Harrison, Nicholas M.
中科院分区：
文献类型：
--
作者：
De Fusco, Giulia C.;Pisani, Leonardo;Harrison, Nicholas M.
在现有实验数据的基础上，提出了一种简单的室温磁性半导体V(TCNE)(2)模型结构。在周期边界条件下，利用混合交换密度泛函理论研究了结构、电子和磁性能。确定了一个自旋极化的铁磁基态，每个公式单位的总自旋为1 μ (B)。相应的电子能带结构和自旋分布分析揭示了V离子与[TCNE]（中心点-）自由基之间的强相互作用，被认为是自旋携带单元。在一个简单的伊辛哈密顿量中，预测了金属与其最近邻配体之间的强反铁磁耦合，这与观察到的高温磁有序一致。计算结果对V（TCNE）异常磁性行为的物理根源提供了有用的见解(2)。
A simple model structure of the room-temperature magnetic semiconductor V(TCNE)(2) is proposed on the basis of available experimental data. The structural, electronic, and magnetic properties are investigated using hybrid-exchange density functional theory within periodic boundary conditions. A spin-polarized ferrimagnetic ground state with a total spin of 1 mu(B) per formula unit is identified. The analysis of the corresponding electronic band structure and spin distribution reveals strong interactions between the V ions and the [TCNE](center dot-) radicals, identified as spin carrying units. Within a simple Ising Hamiltonian, a strong antiferromagnetic coupling between the metal and its nearest-neighbor ligands is predicted which is consistent with the observed high-temperature magnetic ordering. The computed results provide useful insight into the physical origin of the exceptional magnetic behavior of V(TCNE)(2).