Evaluating Moment Tensor Potential in Ag-Cu Alloy: Accuracy, Transferability, and Phase Diagram Fidelity

TL;DR

This study develops and evaluates a Moment Tensor Potential for Ag-Cu alloys, demonstrating improved accuracy and transferability over traditional methods, and accurately predicting phase diagram features.

Contribution

The paper introduces a new MTP model for Ag-Cu alloys that outperforms classical potentials in accuracy and transferability, especially for phase diagram predictions.

Findings

Significant improvements over EAM in defect and surface energetics

Accurate eutectic temperature and composition predictions

Robust transferability across phases and temperatures

Abstract

A Moment Tensor Potential (MTP) has been developed for the Cu-Ag binary alloy and its accuracy, transferability, and thermodynamic fidelity evaluated. The model was trained on a diverse dataset encompassing solid, liquid, and interfacial configurations derived from density functional theory (DFT) calculations. Benchmarking against experiment and DFT data demonstrated significant improvements over the widely used classical Embedded Atom Method (EAM) potential, particularly in predicting defect energetics, surface properties, and the eutectic phase diagram. Despite a slight underestimation of Ag's melting point, the MTP model achieved consistent accuracy across elemental and binary systems without direct fitting to high-temperature phase transitions. The predicted eutectic temperature and composition were found in close agreement with experimental observations. These results establish MTP as a robust framework for modeling immiscible metallic systems and pave the way for its integration into large-scale atomistic simulations where both fidelity and generalizability are essential.