A first principles molecular dynamics study of the relationship between atomic structure and elastic properties of Mg-Zn-Ca amorphous alloys

First-principles molecular dynamics simulations have been carried out for investigating the local and electronic structure and elastic properties of a series of synthesized Mg-Zn-Ca amorphous alloys. The theoretical structures were compared with experimental measurements and the respective local topology analyzed. The computed elastic constants were found to correlate not only to the iconicity (charge transfer) but also to the configurational entropy obtained from the distribution of polyhedral cell volumes. Moreover, the interplay of chemical bonding and structural characteristics was shown to determine the elastic behavior of alloys having the same Mg concentration. The results highlight the significant role of fine tuning the composition in controlling the structural and electronic properties and achieving amorphous alloys with considerable different macroscopic properties