In-situ Observation of Structural Evolution of Zr_60Al_15Ni_25 Bulk Metallic Glass in the Supercooled Liquid Region

摘要

In-situ observation of a structural change in a particular alloy of Zr_60Al_15Ni_25 supercooled liquid has been carried out by a devised x-ray apparatus adopting the geometry of the Debye-Scherrer camera with an imaging plate instead of an x-ray film usually used. A drastic change of coordination numbers in the nearest neighbor region ahs been noted in a certain annealing time that corresponds to the exothermic reaction in the isothermal differential scanning calorimetry (DSC). In contrast, the coordination numbers and atomic distances show little change even for a long annealing time at 693 K just below the glass transition temperature (T_g). Furthermore, the structural parameters of the Zr_60Al_15Ni_25 supercooled liquid were found independent Upon annealing temperature.