On the kinetic and thermodynamic fragility of the Pt60Cu16Co2P22 and Pt57.3Cu14.6Ni5.3P22.8 bulk metallic glasses

The investigations in this study focus on bulk metallic glass (BMG) alloy families based on noble metals like Pt, which are more kinetically fragile than Zr-based BMG systems. Thermophysical properties have been investigated by calorimetry and thermal mechanical analyses for the determination of the specific heat capacity and viscosity, respectively. For the Pt60Cu16Co2P22 and Pt57.3Cu14.6Ni5.3P22.8 BMG compositions consistent Vogel-Fulcher-Tammann (VFT) fits of the viscosity measurements are established, and the temperature dependence of the configurational entropy is calculated from thermodynamic data. Fits to the Adam-Gibbs equation are performed using this configurational entropy change. Their fragile nature is compared to that of Zr-based alloys in terms of structural considerations.