Ultra-Low Glass Transition Temperatures in Ce-Based Bulk Metallic Glasses

Abstract

New (Ce_0.72Cu_0.28)_100−x−yAl_x(Ga,Zn)_y bulk metallic glasses (BMGs) with ultra-low glass transition temperatures and large supercooled liquid regions (ΔT_x) were developed. The addition of Al element into Ce–Cu alloys improves significantly glass formation ability (GFA) of the alloys and the maximum value of ΔT_x is 63 K. The lowest glass transition temperature (T_g) was found in the (Ce_0.72Cu_0.28)_97.5Al_2.5 BMG alloy and the value is 326 K. The addition of Ga and Zn elements into Ce–Cu–Al alloys has no obvious role in the decrease of T_g. However, T_g has a close relation to Ce content and decreases with increasing Ce content. The activation energies of the glass transition are 136 kJ·mol⁻¹ for the (Ce_0.72Cu_0.28)_97.5Al_2.5 glassy alloy and 145 kJ·mol⁻¹ for the Ce_62.5Cu₁₅Al_12.5Ni₁₀ glassy alloys, respectively. The successful fabrication of Ce-based BMGs with ultra-low T_g and large ΔT_x can further extend the potential application of bulk metallic glasses in some special industry fields.