论文部分内容阅读
根据非晶态合金结构的短程有序、Ni和B间存在较强的化学作用、结构中存在B—B键直接相连的实验事实,选择Ni_mB_2(m=1,2,4)原子簇作为非晶态局域结构的计算模型.考虑原子簇间的相互作用,又对[Ni_4B_2]_n(n=1,2,5,7)簇团进行了系统计算.结果表明在所选Ni-B的簇模型中,都是B原子提供电荷给Ni原子,这些均与非晶态合金实验结果和一些理论计算结果相符.簇团的计算结果还表明,小原子簇Ni_4B_2内原子间存在较强的化学键作用,而簇间的相互作用相对较弱,很容易造成对称性破缺而导致产生长程无序,因此Ni-B非晶态可以被看成是由大量小原子簇无序堆砌成的,这一点也同实验事实相吻合.计算结果也表明我们前面工作中所取的和最常见的Ni-B非晶态合金Ni_(64)B_(36)有相似组成的Ni_4B_2原子簇模型能在一定程度上反映Ni-B非晶态合金的局域结构特征.
According to the short-range order of the amorphous alloy structure, there exists a strong chemical interaction between Ni and B, and there are experimental facts that the B-B bonds are directly connected in the structure. The Ni_mB_2 (m = 1, 2, In this paper, we calculated the [Ni_4B_2] _n (n = 1, 2, 5, 7) clusters systematically by considering the interaction between the clusters.Results show that in the selected Ni-B In the cluster model, B atoms provide charges to Ni atoms, which are in good agreement with experimental results and some theoretical results of amorphous alloys.The calculation results of clusters also show that there is a strong chemical bond between atoms in small cluster Ni_4B_2 Interaction between clusters is relatively weak, it is easy to cause the symmetry breaking caused by the resulting long-range disorder, Ni-B amorphous state can be seen as a large number of clusters of small atoms clustered disorder, which The results also agree well with the experimental results. The calculated results also show that the Ni_4B_2 cluster model, which is similar to Ni_ (64) B_ (36) and the most common Ni-B amorphous alloy, On the reflection of Ni-B amorphous alloy local structure characteristics.