Crystal-like Order Stabilizing Glasses: Structural Origin of Ultra-stable Metallic Glasses

TL;DR

This paper reveals that crystal-like medium range order in ultra-stable metallic glasses, formed via vapor deposition, enhances their stability by providing a structural origin contrary to traditional beliefs.

Contribution

It uncovers the structural origin of ultra-stable metallic glasses, linking crystal-like medium range order to their exceptional stability.

Findings

Crystal-like medium range order enhances stability.

Voronoi polyhedron ordering with translational symmetry.

Contradicts conventional wisdom on glass stability.

Abstract

Glasses are featured with a disordered amorphous structure, being opposite to crystals that are constituted by periodic lattices. In this study we report that the exceptional thermodynamic and kinetic stability of an ultra-stable binary ZrCu metallic glass, fabricated by high-temperature physical vapor deposition, originates from ubiquitous crystal-like medium range order (MRO) constituted by Voronoi polyhedron ordering with well-defined local translational symmetry beyond nearest atomic neighbors. The crystal-like MRO significantly improves the thermodynamic and kinetic stability of the glass, which is in opposition to the conventional wisdom that crystal-like order deteriorates the stability and forming ability of metallic glasses. This study unveils the structural origin of ultra-stable metallic glasses and shines a light on the intrinsic correlation of local atomic structure ordering with glass transition of metallic glasses.