Lattice dynamics of wustite (FeO)

Phonon dispersion curves of wustite (FeO) have been measured at room temperature by inelastic neutron scattering in the three high-symmetry directions [001], [110], and [111] of reciprocal space. The experimental curves are interpreted by various lattice-dynamical models including rigid-ion and shell models. The models show that both ions are highly polarizable and that overlap effects seem to play an important role on the shell charge Y₁ of the iron ion, and on the second-neighbor interaction constants. The best-fit model has been applied in calculating structure factors, optical and elastic constants, and the frequency-distribution function.