Structural heritage of metallic glasses and relevant crystals understood via the principal cluster.

Structural heritage between bulk metallic glasses (BMGs) and their relevant crystals has already been acknowledged. But how this kind of heritage is represented is still unclear. In the present paper, firstly, two important characters are considered to determine the principal cluster of crystal, i.e. the atomic-packing efficiency which is evaluated by atomic density radial distribution method and cluster isolation degree which is obtained by the cluster-size reduction rate because of overlapping of clusters in crystal. Then according to these two criteria principal clusters of BMGs Cu-Zr, (Pt,Pd)-Zr and Pd-Si systems are analysed. And the results show that the principal cluster dominates the short-range-order structure of its parent phase as well as the relevant BMG. It is exactly the principal cluster that enters the cluster-plus-glue-atoms units to formulate BMG as [principal cluster](glue atom)_1,3. It proves that the structural heritage between glassy state and relevant crystal is actually reflected by cluster formula which contains the principal cluster. Furthermore, via study structural similarity of metallic glass and relevant crystal, elaborated steps towards quantitatively composition design for BMGs are established. [ABSTRACT FROM AUTHOR]