Dielectric response of a crystal with a damaged surface layer in the longitudinal-transverse splitting region

A model of the dielectric function of a surface layer formed under the mech anical treatment of the crystal surface is considered in the range of the l attice optical vibrations. An approach is proposed based on the continuous distribution of the dipole-active modes in order to take into account the d islocation effect. It is demonstrated that the model used allows one to des cribe satisfactorily the decrease in the reflectivity of polished SiC6H sam ples in the vicinity of the frequency of the transverse optical phonon. (C) 2001 MAIK "Nauka/Interperiodica".