On calorimetric study of the fragility in bulk metallic glasses with low glass transition temperature: (Ce_0.72Cu_0.28) _90-x Al₁₀Fe_x (x = 0, 5 or 10) and Zn ₃₈Mg₁₂Ca₃₂Yb₁₈

Compared with conventional bulk metallic glasses, Ce-based and Zn-based bulk metallic glasses have received considerable attention because of their possible application as structural and functional materials. Kinetic fragility parameter m in amorphous material presents degree of deviations from the Arrhenius law above the glass transition temperature (T_g) of the material. Kinetic fragility parameter (m) and Kauzmann temperature (T _K) in (Ce_0.72Cu_0.28)_90-x Al ₁₀Fe_x (x = 0, 5 or 10) and Zn₃₈Mg ₁₂Ca₃₂Yb₁₈ bulk metallic glasses have been determined by differential scanning calorimetry (DSC). Results show that Zn ₃₈Mg₁₂Ca₃₂Yb₁₈ presents a higher m than (Ce_0.72Cu_0.28)_90-x Al₁₀Fe _x (x = 0, 5 or 10). The activation energies E_g for glass transition are 1.51 eV (x = 0), 1.59 eV (x = 5) and 1.83 eV (x = 10) in (Ce _0.72Cu_0.28)_90-x Al₁₀Fe_x (x = 0, 5 or 10), and 3.59 eV in Zn₃₈Mg₁₂Ca ₃₂Yb₁₈, respectively. The values of E_g increase with increasing the Fe content in (Ce_0.72Cu_0.28) _90-x Al₁₀Fe_x (x = 0, 5 or 10) bulk metallic glasses. Kinetic fragility parameter m of bulk metallic glasses increases with the glass transition temperature T_g of bulk metallic glasses, in agreement with previous investigations.