| 原子簇FenB2(n=1～6)结构和性质的DFT研究(英文) |
| Density Functional Theory Study on Structures and Properties of Cluster FenB2(n=1～6) |
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| 摘要: 本文对上百个FenB2和Fen(n=1～6)原子簇模型进行密度泛函理论计算，用来模拟非晶态合金Fe-B体系的局域结构，并考察类金属元素硼的引入对体系性质的影响。将优化构型的键长和电荷分布与实验数值进行比较，发现本文所使用的原子簇模型在一定程度上可以真实、准确地反映非晶态合金Fe-B体系的局域结构。利用这些构型，我们对其键级、电子、催化以及磁学性质进行了讨论。结果表明：原子簇中均存在着强烈的Fe-B键作用，其中在高铁含量原子簇中Fe-Fe键的作用也较为明显；综合热力学、费米能级及态密度的研究结果，发现原子簇Fe4B2在合成氨和固氮过程中有可能表现出更为优越的催化活性。结合对原子簇Fen和FenB2(n=1～6)平均3d轨道布居数的分析，发现原子簇FenB2(n=1～6)的平均磁矩均小于相应原子簇Fen(n=1～6)的理论数值和纯金属铁的实验数值(5.7～6.0 BM)，也就是说原子簇FenB2(n=1～6)均表现出软磁性。 |
| 关键词: 原子簇FenB2(n=1～6) 非晶态合金 密度泛函理论 费米能级 |
| 基金项目: |
| Abstract: A hundred of clusters FenB2(n=1～6) were designed to simulate Fe-B amorphous alloys. Clusters Fen(n=1～6) were also concerned to study the effect on the addition of metalloid element. After the clusters models were computed by density functional theory, the most stable structures of clusters were gained. Their geometric, catalytic and magnetic properties have been analyzed and discussed. From the results, it was found that the geometries of most stable clusters FenB2(n=1～6) were isosceles triangle, diamond, triangle dipyramid, oblique triangular prism，triangular prism with one hat, and triangular prism with two hats, respectively. Basing on the bond lengths and electronic properties, the clusters models in the present paper could reflect the local structures of Fe-B amorphous alloys perfectly to a certain extent. The interactions of bond Fe-B were stronger, and the bonds between metal atoms also took some action to the stability of system in clusters of rich iron content. Basing on the studies of thermodynamics, Fermi level and DOS, cluster Fe4B2 could appear more excellent catalytic properties in ammonia synthesis and nitrogen fixation process among the clusters FenB2(n=1～6). After the study of average 3d population of clusters, the average magnetic moments were gained. The calculated average magnetic moments of clusters FenB2(n=1～6) were less than the relevant theory calculation results of clusters Fen(n=1～6) and the experimental value of pure metal Fe (5.7～6.0 B.M.), and totally appeared soft magnetism. |
| Keywords: clusters FenB2(n=1～6) amorphous alloys density functional theory Fermi level |
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| 方志刚,胡红智.原子簇FenB2(n=1～6)结构和性质的DFT研究(英文)[J].无机化学学报,2006,22(4):598-606. |
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