Activation-relaxation technique study on beta-relaxation in La55Ni20Al25 and Cu46Zr46Al8 metallic glasses

作者：Xu, H. Y.; Li, M. Z.^*

来源：Intermetallics, 2018, 94: 10-16.

DOI：10.1016/j.intermet.2017.12.017

• Metallic glasses
• beta-relaxation
• Potential energy landscape
• Activation-relaxation technique

Activation-relaxation technique combined with molecular dynamics simulations was employed to investigate 0 relaxation behavior in La55Ni20Al25 and Cu46Zr46Al8 model metallic glasses (MGs) for exploring the underlying mechanism. It is found that the activation energies are much smaller in La55Ni20Al25 MG, indicating that beta-relaxation can be more easily activated in La55Ni20/Al-25 MG. It is also revealed that in both MGs, string-like diffusion dominates the atomic motions in beta-relaxation. However, in different MGs, the string-like motions are found to involve atoms with different structure features, which could be the underlying structural basis of beta-relaxation mechanism. In addition, because of very low activation energies, atomic hopping and cooperative rearrangements in La55Ni20Al25 MG also have significant impact on beta-relaxation. However, such atomic motions are much weaker in Cu46Zr46Al8 MG, due to higher activation energies. These findings establish a physical link for activation energy and atomic motions in beta-relaxation to atomic structures, and provide new understanding of beta-relaxation mechanism in MGs.

• 出版日期2018-3
• 单位中国人民大学