Correlation between the chemical short-range order and binding energy of Cu-centred CunZr13−n(n = 6,7,8,9) icosahedral clusters in metallic glass

Abstract

The correlation between shell atomic arrangement and binding energy of Cu-centred CunZr13−n (n = 6,7,8,9) icosahedral clusters is systematically investigated by chemical short-range order parameters (Spaepen–Cargill parameters δCuZr and Warren–Cowley parameters ) and first principles calculations. It is found that the shell homogeneous atoms prefer to bond each other and heterogeneous atoms tend to segregation in stable Cu-centred Cu–Zr icosahedral cluster. And analysis show that the shell atomic arrangement and energy stability of Cu-centred CunZr13−n (n = 6,7,8,9) icosahedral clusters are non-linearly related. Moreover, for , we found that the smaller the δCuZr value is, the more the number of homogeneous atomic bond pairs is. Whereas, for , the bigger the value of δCuZr is, the more the number of heterogeneous atomic bond pairs is. For , we also found an identical rule only the description of physical significance of positive and negative of parameter are different. That is to say when , the bigger the value of is, the larger the number of bond pairs of homogeneous atoms is. Whereas, for , the more negative the value of is, the larger the number of bond pairs of heterogeneous atoms is. This is a deeper development for the physical significance of Spaepen–Cargill and Warren–Cowley parameter.