Theoretical study on the local structure and properties of electron transfer of Ni-B amorphous alloy

The electron - transfer between Ni and B is an open issue in the study of N i - B amorphous alloy. This problem is very important in the understanding of its catalytic behavior and other related properties. According to the ex perimental facts of the presence of direct B - B contact, a very strong int eraction between Ni and B and short - range - ordering in the amorphous all oy, NimB2 (m = 1,2,4) cluster models were chosen as the models of local str ucture of amorphous alloy Ni - B, and they were calculated for examining th eir structure and electronic properties. Considering the interaction betwee n the clusters, we also performed the calculation of the group of clusters [Ni4B2](n) (n = 1,2,5,7). The results of the calculations show that boron i s a electron - donor in the Ni - B amorphous alloy, while nickel is a elect ron - acceptor, which agrees well with the experimental results and previou s theoretical result. Meanwhile, the results also show that there exists qu ite strong interaction of chemical bond in the cluster, while the interacti ons between the clusters is relatively weak. Thus, it could be concluded th at the Nb4B2 cluster model is able to reflect the character of local struct ure of Ni - B (Ni64B36) amorphous alloy partly.