Geometrical Frustration in Liquid Fe and Fe-Based Metallic Glass

TL;DR

This study uses ab-initio simulations to analyze local geometric order in liquid Fe and Fe-based metallic glasses, revealing how alloying elements influence icosahedral frustration and local structure.

Contribution

It provides new insights into how alloying elements modulate geometric frustration and local order in Fe-based metallic glasses using ab-initio methods.

Findings

Fe exhibits greater icosahedral order than Cu.

Alloying with B and Zr controls local icosahedral frustration.

Icosahedral disclination defects are more compatible with BCC environments.

Abstract

We investigate short rane order in liquid and supercooled liquid Fe and Fe-based metallic glass using ab-initio simulation methods. We analyze the data to quantify the degree of local icosahedral and polytetrahedral order and to understand the role of alloying in controlling the degree of geometric frustration . Comparing elemental Fe to Cu we find that the degree of icosahedral order is greater in Fe than in Cu, possibly because icosahedral disclination line defects are more easily incorporated into BCC environments than FCC. In Fe-based metallic glass-forming alloys (FeB and FeZrB) we find that introducing small concentrations of small B atoms and large Zr atoms controls the frustration of local icosahedral order.