Hand in Hand Evolution of b-relaxation and Boson Peak in Metallic Glasses

TL;DR

This study reveals a direct relationship between the boson peak and beta-relaxation in metallic glasses, showing they share a common structural origin related to loosely packed regions, through atomic packing tuning.

Contribution

It demonstrates a linear correlation between boson peak temperature and beta-relaxation activation energy in metallic glasses, linking their structural origins.

Findings

Boson peak evolves with beta-relaxation upon microalloying.

Linear correlation between boson peak temperature and beta-relaxation activation energy.

Shared structural origin in loosely packed regions of metallic glasses.

Abstract

Boson peak and beta-relaxation are two intrinsic and markedly different dynamic modes of glasses, and their structural origins are long-standing issues. Through tuning atomic packing of a model metallic glass with microalloying of different types of elements, we find that low-temperature boson heat capacity peak evolves hand in hand with high-temperature beta-relaxation. A linear correlation between the boson peak temperature and the activation energy of beta-relaxation is disclosed. The coupling of the boson peak and the beta-relaxation indicates their common structural origin of the loosely packed regions in metallic glasses.