Abstract
The fast dynamic properties of the surface of metallic glasses(MGs)play a critical role in determining their potential appli-cations.However,due to the significant difference in thermal history between atomic simulation models and laboratory-made samples,the atomic-scale behaviors of the fast surface dynamics of MGs in experiments remain uncertain.Herein,we prepared model MG films with notable variations in thermal stability using a recently developed effiicient annealing protocol,and investigated their atomic-scale dynamics systematically.We found that the dynamics of surface atoms remain invariant,whereas the difference in dynamical heterogeneity between surface and interior regions increases with the improvement of thermal stability.This can be associated with the more pronounced correlation between atomic activation energy spectra and depth from the surface in samples with higher thermal stability.In addition,dynamic anisotropy appears for surface atoms,and their transverse dynamics are faster than normal components,which can also be interpreted by activation energy spectra.Our results reveal the presence of strong liquid-like atomic dynamics confined to the surface of laboratory-made MGs,illuminating the underlying mechanisms for surface engineering design,such as cold joining by ultrasonic vibrations and superlattice growth.
基金项目
国家自然科学基金(52101201)
重庆市自然科学基金(cstc202ljcyjmsxmX0369)
Science Fund for Scientific and Technological Innovation Team of Shaanxi Province(2021TD-14)
国家自然科学基金(T2325004)
国家自然科学基金(51801046)
Beijing Computational science Research Center(CSRC)()
维普
万方数据