In-situ observation of structural evolution of Zr60Al15Ni25 bulk metallic glass in the supercooled liquid region

Abstract

In-situ observation of a structural change in a particular alloy of Zr60Al15Ni25 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 has 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 (Tg). Furthermore, the structural parameters of the Zr60Al15Ni25 supercooled liquid were found independent upon annealing temperature.