液体和非晶态Ni_(64)B_(36)合金结构的从头算分子动力学模拟

Ab initio Molecular Dynamics Simulation of Structures of Ni_(64)B_(36) Alloys in Liquid and Amorphous Phase

运用从头算分子动力学模拟了液体以及猝冷后形成的非晶态Ni64B36合金体系,得到了它们的对相关函数、结构因子、键对分析方面的结构信息,与实验结果相当一致;结果表明,猝冷得到的合金性质与液体合金性质相似,为非晶态结构.B原子多数以B—B双原子成键形式分散于Ni原子构成的骨架中.电子态密度分析表明,Ni3d电子最活泼,因此在合金中Ni为活性位.轨道电荷分析从电子结构角度揭示了在NiB催化剂中B作为修饰剂的机理.

Liquid and amorphous Ni64B36 alloys were simulated by ab initio molecular dynamics. The system properties such as pair correlation function, structure factors and bond pair analysis have been obtained, and our results agree with the corresponding experimental ones very well. It is indicated that the amorphous Ni64B36 alloy could be prepared by rapid quenching and its structure is similar to that of liquid alloy. B has been dispersed very well within Ni. The analysis of electronic density of states showed that the d electrons of Ni atoms are the most active, hence Ni atoms are active sites. Orbital population analysis reveals the modification mechanism of B atoms in NiB catalyst as modifiers.