Liquid fragility and characteristic of the structure corresponding to the prepeak of AlNiCe amorphous alloys

Abstract

Liquid fragility and its relation to characteristic of the structure corresponding to the prepeak have been investigated for the AlNiCe alloy system. Thermal analysis shows that in the Al-rich ternary system, the fragility strength exhibits a strong dependence on the Ce content. A close correlation between liquid fragility and the stability of the structure corresponding to the prepeak, as well as the correlation length, is observed for these alloys. Strong liquids correspond to stable medium-range order structure, which results from large energy of cluster breakage. It has been found that the influence of Ce additions on the stability of the structure corresponding to the peak is completely opposite to that on the thermal stability of the glasses. Besides, no obvious relationship exists between dynamic fragility and the glass-forming ability. These unexpected observations have been explained in terms of structural relaxation of the clusters in liquids exhibiting different dynamic fragilities.