Evolution of atomic structure in Al75Cu25 liquid from experimental and ab initio molecular dynamics simulation...

Area of Science:

• Materials Science
• Physical Chemistry
• Condensed Matter Physics

Background:

• Understanding the behavior of liquid alloys is crucial for materials processing and applications.
• Aluminum-copper alloys are technologically significant, but their liquid-state properties require further investigation.

Purpose of the Study:

• To investigate the structural and thermodynamic properties of bulk liquid Al(75)Cu(25) alloy.
• To determine if a liquid-liquid phase transition occurs in this alloy within a specific temperature range.

Main Methods:

• Combined experimental techniques: X-ray diffraction and electrostatic levitation.
• Computational approach: Ab initio molecular dynamics simulations.
• Analysis of atomic structure using Honeycutt-Andersen index and Voronoi tessellation.

Main Results:

• Experimental and simulation results showed excellent agreement.
• No abnormal changes were detected in specific heat capacity, total hemispheric emissivity, or density.
• Ab initio molecular dynamics simulations confirmed experimental structure factors.
• Icosahedral-like atomic clusters were found to be prevalent and continuously evolving.

Conclusions:

• The study provides strong evidence against a liquid-liquid transition in bulk liquid Al(75)Cu(25) alloy.
• The observed atomic structure suggests a stable, albeit dynamic, cluster arrangement in the liquid state.