Pressure-induced elastic anomaly in a polyamorphous metallic glass

摘要

The pressure-induced transitions discovered in metallic glasses (MGs) have attracted considerable research interest offering an exciting opportunity to study polyamorphism in densely packed systems. Despite the large body of work on these systems, the elastic properties of the MGs during polyamorphic transitions remain unclear. Here, using an in situ high-pressure ultrasonic sound velocity technique integrated with x-ray radiography and x-ray diffraction in a Paris-Edinburgh cell, we accurately determined both the compressional and shear wave velocities of a polyamorphous Ce_(68)Al_(10)Cu_(20)Co_2 MG up to 5.8 GPa. We observed elastic anomalies of a MG with minima (at ~ 1.5 GPa) in the sound velocities, bulk modulus, and Poisson's ratio during its polyamorphic transition. This behavior was discussed in comparison to the elastic anomalies of silica glass and crystalline Ce. Published by AIP Publishing.