Study on the boson peak in bulk metallic glasses

The low-temperature specific heat (low-T C-p) and other properties of a series of representative bulk metallic glasses (BMGs) were studied. The pronounced low-T C-p anomalies associated with the boson peak (BP) in the representative BMGs were observed. The BMG samples were annealed and quenched near the glass transition temperatures, and the effect of isothermal annealing for different times and quenching at different cooling rates on the low-T C-p anomalies were studied. We observed that the BP is affected by annealing and quenching processes. It is a possible explanation that the BP mainly originated from the random dense cluster-packing structure. The origin of the C-p anomalies is interpreted with the harmonic localized modes based on the random dense-packed atomic cluster structure of BMGs. The clear correlation between the maximum value of BP [(C-p-gamma T)/T-3](max) and its position T-max further supports the model. (c) 2008 American Institute of Physics.