Continuously variable atomic structure in monatomic metallic glasses through active icosahedral dynamics below glass transition temperature

As a ubiquitous structural feature in metallic glasses, icosahedral clusters are known to be arrested below the glass transition temperature (T-g), and correspondingly, the atomic structure of a solid metallic glass is generally fixed, even though interatomic spacing varies slightly with temperature. Here, we report our discovery from large molecular dynamics simulations that icosahedral clusters in monoatomic metallic glasses (e.g., Ta, V) are capable of adapting their population and geometry to changing temperature in a wide range spanning more than 1000 degrees below T-g. This enables variation of the atomic structure of the metallic glasses directly in the solid state and provides an opportunity to tailor the materials' performance in functional devices, despite precautions needed to avoid undesired crystallization. The surprising discovery of active icosahedral dynamics far below T-g has important implications for the physical understanding of glassy metallic systems. Published by AIP Publishing.