# Tuning the glass-forming ability of metallic glasses through energetic frustration

## TL;DR

This study uses molecular dynamics simulations to explore how energetic frustration influences the glass-forming ability of metallic glasses, revealing key energetic variables that correlate with critical cooling rates.

## Contribution

The paper introduces a quantitative analysis of energetic frustration effects on GFA, identifying specific energetic variables that predict critical cooling rates in binary alloys.

## Key findings

- Weak correlation between heat of mixing and critical cooling rate.
- Strong correlation between GFA and energetic variables _- and _{AB}.
- A combined energetic variable collapses data over 4 orders of magnitude.

## Abstract

The design of multi-functional BMGs is limited by the lack of a quantitative understanding of the variables that control the glass-forming ability (GFA) of alloys. Both geometric frustration (e.g. differences in atomic radii) and energetic frustration (e.g. differences in the cohesive energies of the atomic species) contribute to the GFA. We perform molecular dynamics simulations of binary Lennard-Jones mixtures with only energetic frustration. We show that there is little correlation between the heat of mixing and critical cooling rate $R_c$, below which the system crystallizes, except that $\Delta H_{\rm mix} < 0$. By removing the effects of geometric frustration, we show strong correlations between $R_c$ and the variables $\epsilon_- = (\epsilon_{BB}-\epsilon_{AA})/(\epsilon_{AA}+\epsilon_{BB})$ and ${\overline \epsilon}_{AB} = 2\epsilon_{AB}/(\epsilon_{AA}+\epsilon_{BB})$, where $\epsilon_{AA}$ and $\epsilon_{BB}$ are the cohesive energies of atoms $A$ and $B$ and $\epsilon_{AB}$ is the pair interaction between $A$ and $B$ atoms. We identify a particular $f_B$-dependent combination of $\epsilon_-$ and ${\overline \epsilon}_{AB}$ that collapses the data for $R_c$ over nearly $4$ orders of magnitude in cooling rate.