The temperature-dependent elastic properties of B2-MgRE intermetallic compounds from first principles

TL;DR

This study uses first-principles DFT calculations to analyze how the elastic properties of B2-MgRE intermetallic compounds vary with temperature, emphasizing thermal expansion effects and validating results against experimental data.

Contribution

It provides the first comprehensive temperature-dependent elastic properties of MgRE intermetallics from first-principles calculations, including thermal effects and comparison with experimental data.

Findings

Elastic constants decrease with temperature.

Good agreement with experimental data at 0K.

Elastic moduli approach linearity at higher temperatures.

Abstract

Using the density functional theory (DFT) formulated within the framework of the plane-wave basis projector augmented wave (PAW) method, the temperature-dependent elastic properties of MgRE (RE=Y, Dy, Pr, Sc, Tb) intermetallics with B2-type structure are presented from first-principles. Our calculations are based on the fact that the elastic moduli as a function of temperature mainly results from thermal expansion. The comparison between the predicted results and the available experimental data for a benchmark material NiAl provides good agreements. At $T=0K$, our calculated values of lattice parameter and elastic moduli for MgRE intermetallics show excellent agreement with previous theoretical results and experimental data. While temperature increases, we find that the elastic constants decrease and approach linearity at higher temperature and zero slope around zero temperature.