Glass Formation Ability and Kinetics of the Gd₅₅Al₂₀Ni₂₅ Bulk Metallic Glass

We report a new bulk glass-forming alloy Gd₅₅Al₂₀Ni₂₅. The bulk sample of the alloy is prepared in the shape of rods in diameter 2mm by suction casting. The rod exhibits typical amorphous characteristics in the x-ray diffraction pattern, paramagnetic property at 300K, distinct glass transition and multi-step crystallization behaviour in differential scanning calorimetry traces. The glass formation ability of the alloy is investigated by using the reduced glass transition temperature T_rg and the parameter γ. Kinetics of glass transition and primary crystallization is also studied. The fragility parameter m obtained from the Vogel--Fulcher--Tammann dependence of glass transition temperature T_g on lnФ (Ф is the heating rate) classifies the bulk metallic glasses into the intermediate category according to Angell's classification.