Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1600476 | Intermetallics | 2012 | 5 Pages |
We have investigated the finite temperature elastic properties of AlRE (RE = Y, Tb, Pr, Nd, Dy) with B2-type structures from first principles. The phonon free energy and thermal expansion are obtained from the quasiharmonic approach based on density-functional perturbation theory. The static volume-dependent elastic constants are obtained from energy–strain functions by using the first-principles total-energy method. The comparison between our predicted results and the ultrasonic experimental data for a benchmark material Al provides excellent agreements. At T = 0 K, our calculated values of lattice equilibrium volume and elastic moduli of our calculated AlRE (RE = Y, Tb, Pr, Nd, Dy) intermetallics agree well with the previous theoretical results. The temperature-dependent elastic constants exhibit a normal behavior with temperature, i.e., decrease and approach linearity at higher temperature and zero slope around zero temperature. Furthermore, the anisotropy ratio and sound velocities as a function of temperature have also been discussed.
► The finite temperature elastic constants of AlRE are calculated from first principles. ► The quasiharmonic approach is used to calculate thermal expansion. ► We discuss that the anisotropy ratio as a function of temperature. ► The temperature-dependent sound velocities are investigated.