Strong-Coupling Theory of Paraelectric Impurities in Alkali Halides

Abstract

The excitation energies of dipolar impurities such as O${\mathrm{H}}^{-}$ or C${\mathrm{N}}^{-}$ in alkali halides are calculated, using a modification of the Devonshire model in which it is assumed that the major contribution to the dipolar potential is due to the asymmetrical distortion of the lattice by the dipole.