Structure and Stability of an Amorphous Metal

TL;DR

This study uses advanced molecular dynamics simulations to analyze the structure and stability of amorphous nickel, revealing how quenching rates influence crystalline order and glass stability.

Contribution

It introduces a novel method for characterizing local order and demonstrates differences in amorphous structure compared to previous pair potential simulations.

Findings

Slower quenching leads to more crystalline order.

Fewer icosahedra are present in less stable glasses.

Amorphous structure is characterized by small crystalline clusters within a liquid-like matrix.

Abstract

Using molecular dynamics simulations, with a realistic many-body embedded-atom potential, and a novel method to characterize local order, we study the structure of pure nickel during the rapid quench of the liquid and in the resulting glass. In contrast with previous simulations with pair potentials, we find more crystalline order and fewer icosahedra for slower quenching rates, resulting in a glass less stable against crystallization. It is shown that there is not a specific amorphous structure, only the arrest of the transition from liquid to crystal, resulting in small crystalline clusters immersed in an amorphous matrix with the same structure of the liquid.