Impact of Plastic Deformation and Shear Band Formation on the Boson Heat Capacity Peak of a Bulk Metallic Glass

The effect of annealing on the low-temperature heat capacity of a bulk Pd38.5Ni40P21.5 metallic glass is investigated for as-quenched and deformed (rolled) states. Although the boson heat capacity peak increases with increasing strain, it relaxes faster and to a lower level compared to that of the as-quenched state after annealing treatments both below and above the glass transition temperature T-g. The glass is found to retain a certain "memory" on the room-temperature plastic deformation even after annealing above T-g. Indications for two counteracting processes that might be related to different types of shear bands are observed.