Low-density to high-density transition inCe75Al23Si2 metallic glass

Abstract

Using in situ high-pressure x-ray diffraction (XRD), we observed a pressure-induced polyamorphictransition from the low-density amorphous (LDA) state to the high-density amorphous (HDA) statein Ce75Al23Si2 metallic glass at about 2 GPa and 300 K. The thermal stabilities of both LDA and HDAmetallic glasses were further investigated using in situ high-temperature and high-pressureXRD, which revealed different pressure dependences of the onset crystallization temperature(Tx) between them with a turning point at about 2 GPa. Compared withCe75Al25 metallic glass, minor Si doping shifts the onset polyamorphic transition pressure from 1.5 to2 GPa and obviously stabilizes both LDA and HDA metallic glasses with higherTx and changestheir slopes dTx/dP. The results obtained in this work reveal another polyamorphous metallic glass system byminor alloying (e.g. Si), which could modify the transition pressure and also properties ofLDA and HDA metallic glasses. The minor alloying effect reported here is valuable for thedevelopment of more polyamorphous metallic glasses, even multicomponent bulkmetallic glasses with modified properties, which will trigger more investigations inthis field and improve our understanding of polyamorphism and metallic glasses.