Digital magnetic moment of tetrahedrally bonded half-metallic nanoclusters
Digital magnetic moment of tetrahedrally bonded half-metallic nanoclusters
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DOI：
10.1103/physrevb.69.214429
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发表时间：
2004-06
影响因子：
3.7
通讯作者：
M. Nakao
中科院分区：
文献类型：
--
作者：
M. Nakao
我们调查的半金属性和本地化的自旋磁矩为个别纳米团簇的锌-过渡金属磷属元素化物和硫属元素化物TX（T= V，Cr和Mn; X= N，P，As，Sb，S，Se和Te）使用第一性原理分子轨道计算。这些纳米团簇，以及散装，显示半金属铁磁行为的范围很广的键长，否则，反铁磁排列是稳定的。孤立的半金属纳米团簇TkX的总磁矩结果为sZtot = 8dk + s4 DZdsk = 8dk，d，单位为mB，其中Ztot是每个分子式单元的价电子总数，对于磷属元素化物，DZ =1，对于硫属元素化物，DZ= 2。这种依赖性来自簇表面上的阴离子悬挂混合物。阴离子位点诱导的反平行磁矩用键轨道模型解释;阳离子d态和阴离子p态之间的杂交效应在键轨道的多数自旋态中产生空穴。当纳米团簇嵌入具有共同阴离子的晶格匹配的化合物半导体中时，总磁矩接近sZtot = 8dkmB。在纳米团簇的边界处保持半金属性，而没有任何界面态的迹象，表明接触的欧姆性质。
We investigate the half metallicity and localized spin magnetic moments for individual nanoclusters of zinc-blende transition-metal pnictides and chalcogenides TX (T= V, Cr, and Mn; X= N, P, As, Sb, S, Se, and Te) using first-principles molecular-orbital calculations. These nanoclusters, as well as the bulk, show half-metallic ferromagnetic behavior for a wide range of bond lengths; otherwise, an antiferromagnetic arrangement is stabilized. The total magnetic moment of an isolated half-metallic nanocluster TkX, turns out to be sZtot ˛8 dk + s 4˛ DZdsk ˛ ,d in units of mB, where Ztot is the total number of valence electrons per formula unit, DZ =1 for pnictides, and DZ= 2 for chalcogenides. This , dependence results from anion dangling hybrids on the cluster surface. Induced antiparallel magnetic moments at anion sites are interpreted in terms of a bond-orbital model; the hybridization effect between cation d states and anion p states creates holes in the majority-spin states of the bond orbitals. When the nanocluster is embedded in a lattice-matched compound semiconductor with a common anion, the total moment approaches sZtot ˛8 dkmB. Half metallicity is maintained at the boundary sites of the nanocluster without any sign of interface states, suggesting the Ohmic nature of the contact.