  The phonon and thermodynamic properties of rare-earth-aluminum intermetallics
AlRE (RE=Y, Gd, Pr, Yb) with B2-type structure are investigated by performing
density functional theory and density functional perturbation theory within the
quasiharmonic approximation. The phonon spectra and phonon density of states,
including the phonon partial density of states and total density of states,
have been discussed. Our results demonstrate that the density of states is
mostly composed of Al states at the high frequency. The temperature dependence
of various quantities such as the thermal expansions, the heat capacities at
constant volume and constant pressure, the isothermal bulk modulus, and the
entropy are obtained. The electronic contribution to the specific heat is
discussed, and the presented results show that the thermal electronic
excitation affecting the thermal properties is inessential.
