Engineering liquid-liquid interfaces for high-entropy alloy synthesis

TL;DR

This paper introduces a novel liquid-liquid interface engineering method for synthesizing high-entropy alloys with controlled properties, enabling alloying of immiscible metals under mild conditions and real-time observation of alloying processes.

Contribution

It presents a general, controllable synthesis route for high-entropy alloys using liquid-liquid interfaces, allowing precise control over crystallinity, morphology, and composition.

Findings

Successful synthesis of HEAs with up to 20 elements.

Real-time observation of hydrogen-enhanced mixing.

Controlled crystallinity and morphology achieved.

Abstract

High-entropy alloys (HEAs) with various promising applications have attracted significant interest. However, alloying immiscible metal elements while controlling the morphology and crystallinity remains extremely challenging. We report a general route, by engineering liquid-liquid interfaces, for the synthesis of HEAs with controlled crystallinity (single crystal, mesocrystal, polycrystal, amorphous), morphology (0-dimension, 2-dimension, 3-dimension), and high composition diversity (20 elements) under mild conditions (room temperature to 80 degrees celsius). As reactions can be spatially confined at the liquid-liquid interface, it provides an opportunity to control the kinetics and reduce the alloying temperature. Our real-time observation of the alloying of HEAs reveals hydrogen-enhanced mixing and isothermal solidification that kinetically traps the mixing states due to composition changes. The concept of liquid-liquid interface engineering can be applied to obtain other high-entropy compounds.