Structural Properties and Relative Stability of (Meta)Stable Ordered, Partially-ordered and Disordered Al-Li Alloy Phases

TL;DR

This paper uses advanced density-functional theory techniques to accurately predict the structural properties and stability of various phases in the Al-Li alloy system, addressing previous inconsistencies.

Contribution

It introduces an optimal basis-set approach to DFT that improves predictions of phase stability and structural properties in complex alloys like Al-Li.

Findings

DFT results align well with experimental data

Improved prediction of phase stability in Al-Li alloys

Method enables reliable study of complex alloy phases

Abstract

We resolve issues that have plagued reliable prediction of relative phase stability for solid-solutions and compounds. Due to its commercially important phase diagram, we showcase Al-Li system because historically density-functional theory (DFT) results show large scatter and limited success in predicting the structural properties and stability of solid-solutions relative to ordered compounds. Using recent advances in an optimal basis-set representation of the topology of electronic charge density (and, hence, atomic size), we present DFT results that agree reasonably well with all known experimental data for the structural properties and formation energies of ordered, off-stoichiometric partially-ordered and disordered alloys, opening the way for reliable study in complex alloys.