Griffiths-like region explains the dynamic anomaly in metallic glass-forming liquids

TL;DR

This study uses simulations to reveal thermodynamic fluctuations near a Griffiths-like region, explaining the dynamic anomalies in metallic glass-forming liquids and their violation of the Stokes-Einstein relation.

Contribution

It provides a novel thermodynamic-fluctuation perspective on dynamic anomalies in metallic glasses, highlighting a Griffiths-like region as a key factor.

Findings

Thermodynamic fluctuations are significant near a specific region in metallic liquids.

These fluctuations are linked to the violation of the Stokes-Einstein relation.

A Griffiths-like region explains the dynamic anomalies observed.

Abstract

Complex fluids such as water exhibits many anomalous phenomena, and research suggests these properties are closely tied to critical fluctuations near the liquid-liquid phase transition critical point (LLCP). However, whether a similar LLCP exists in metallic glass-forming liquids, which are notable for their high atomic coordination, remains an open question. Although dynamic anomalies such as the breakdown of the Stokes-Einstein (SE) relation have often been attributed to dynamic heterogeneity or structural changes, relatively few studies have analyzed these anomalies from a thermodynamic-fluctuation perspective. This gap probably stems from the challenges in detecting density-driven phase transitions in such systems. Here, we use numerical simulations to explore the thermodynamic mechanisms behind dynamic anomalies in a prototypical metallic glass-forming melt. We observe substantial thermodynamic fluctuations near a particular region, which likely corresponds to a frustration state of liquid, vapor, and glass. These fluctuations may contribute to the violation of the SE relation. Our findings offer a fresh Griffiths-like perspective on the dynamic anomalies seen in supercooled metallic liquids, and shed new light on their underlying mechanisms.