  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 is 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 = 0K, 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 has also been discussed.
