lattice vibrations induced by impurities in polar crystals
abstract
the effect of a single or a pair of polarizable
impurities on the vibrational frequencies of a solid is
investigated. it is shown that the introduction of impurities
alters the energy of the crystal due to the coupling of the
dipoles through the polarization of the impurities and perturbs
the longitudinal-optical frequencies of the crystal. both the
perturbed frequency and the change in energy of the crystal are
calculated explicitly and the results are examined at very small
and very large separation of the impurities to demonstrate
agreement with the literature.
collections
- retrospective theses [1604]