密度泛函理论计算GenFe(n=1—8)团簇的基态结构及其磁性

基于第一性原理，利用密度泛函理论中的广义梯度近似 (GGA)对Ge_nFe(n=1—8)团簇进行了结构优化、能量及频率的计算，得到了 Ge_nFe(n=1—8)团簇在不同自旋多重度下的平衡构型及其基态结构.结果表明：Ge_nFe混合团簇的平均结合能明显比相应纯锗团簇的平均结合能有所增大，即掺杂Fe原子可以提高锗团簇的稳定性；纯锗团簇的基态除了Ge₂为自旋三重态外其他均为单重态，而混合团簇Ge_nFe(n=1—8)的基态均为自旋三重态；对Ge_nFe(n=1—8)团簇的磁性做了较系统的研究，发现团簇总磁矩随团簇尺寸增大基本稳定在2μ_B (只有Ge₈Fe的总磁矩2.391μ_B较明显地偏离了2μ_B)，另外团簇中Fe原子的磁矩在2.5μ_B左右振荡. 关键词： nFe团簇')" href="#">Ge_nFe团簇 密度泛函理论(DFT) 自旋多重度 磁矩

Ground-state structures and magnetisms of GenFe(n=1-8) clusters: The density functional investigations

The geometries, total energies, and frequencies of Ge_nFe(n=1—8) clusters have been systematically investigated using density functional theory with the generalized gradient approximation, and the equilibrium geometries at different spin multiplicities as well as the ground-state structures have been determined. The calculated results indicate that the average binding energy of the Ge_nFe clusters is obviously higher than that of the corresponding pure Ge_n clusters, which implies that the doping of Fe atom can enhance the stability of the germanium clusters. Except for Ge₂ with triplet multiplicity, the ground-state structures of pure germanium clusters are spin singlet; however, the Ge_nFe clusters are all triplet. We also systematically studied magnetic properties of Ge_nFe clusters and found that the total magnetic moment of cluster stabilizes at about 2μ_B (except for Ge₈Fe with total moment of 2.391μ_B), and the magnetic moment of Fe atom stabilizes around 2.5μ_B.