Using phonon density-of-states data from the literature, the vibrational en
tropies of formation were calculated for 32 different alloys and intermetal
lic compounds in the harmonic approximation. The vibrational entropies of f
ormation span a wide range from -0.64k(B) to +0.55k(B) atom(-1) The change
in vibrational entropy when a minority species is substituted for a majorit
y species was also calculated. These vibrational entropies of alloying rang
ed from -0.39k(B) to +1.0k(B) atom(-1). Some correlations of the vibrationa
l entropies to the thermophysical properties of the elements are reported.
Correlations of vibrational entropies to predictions of a bulk Debye model
were unsuccessful because the Debye temperature emphasizes a minority of ph
onons that have low energies. Good correlation was found between the vibrat
ional entropy of formation and the differences in metallic radii of the all
oy species. The vibrational entropies of alloying for L1(2), A15 and Laves
phase compounds were most successfully correlated to the mass ratio of the
solute and matrix atoms.