On the atomic structure of Zr-Ni and Zr-Ni-Al metallic glasses

International audienceUsing real space pair distribution functions derived from high precision x-ray diffraction data, the local atomic structure of Zr-Ni and Zr-Ni-Al metallic glasses was investigated. Unlike Zr-Cu metallic glasses, the structure of Zr-Ni metallic glasses cannot be approached with an ideal solution model, due to strong attractive interactions between Zr- and Ni atoms, which promote chemical short range order. Addition of Al can be beneficial for the glass forming ability of Zr-Ni metallic glasses. The atomic size of Al, being intermediate to those of Zr- and Ni and the strongly attractive interactions between Zr-Al and Zr-Ni atoms can lead to highly negative volumes of mixing Delta V/(mix), and to denser atomic structures, reduced atomic mobility in the liquid and easier suppression of crystallization in the undercooled liquid stat