Atomic order evolution on the length scale in metallic glasses

Abstract

Possessing the short-range order but lacking of the long-range order is ubiquitous in the atomic structures of metallic glasses. We compare the inherent structures of metallic glasses with different compositions simulated via the molecular dynamics to explore the order evolution at different length scales. The short-range order mostly contributes to the dominant clusters with higher local order metrics, which is not universal for all atoms. Only the Bergman type of medium-range order centered by icosahedral clusters is clearly identified, resulting in a much lower degree of medium-range order. With the further increase of length scale, locations of neighboring atoms are less correlated, including the icosahedral cluster network. The absence of long-range order is the result of the decreasing evolution of order at the length scale.