Interatomic force constants and lattice vibrations of AlP,AlAs and AlSb

The interatomic force constants and the phonon dispersion curves of AlP, AlAs, and AlSb are obtained from the electronic theory of solids by using our presented binding force, which includes mainly covalent interactions in the pseudopotential formalism and partially ionic interactions. The potential-parameter, effective ionic charge and ionic fraction of AlP and AlAs are estimated from those of AlSb and other III–V tetrahedrally- bonded compounds in spite of no experimental information on the band- calculation and the neutron scattering data of AlP and AlAs. Numerical data for the crystal energy of AlP and AlAs are in good agreement with the observed data, and the obtained results for the phonon dispersion curves and bulk modulus are useful to study the lattice dynamics and anharmonic properties of these compounds.