Modification of electric dipole domains on mica by excimer laser irradiation

We report on microscopic structural changes of a mica surface as a result of irradiation by an KrF excimer laser. All the peaks of a low energy electron diffraction (LEED) pattern show a threefold splitting due to the build-up of strong surface dipole fields following cleavage of mica. The shape of this splitting as well as the half width of individual LEED spots are modified by the excimer laser. We conclude from our measurements that the laser irradiation leads to orientation dependent desorption of defects from the surface, resulting in large and homogeneous electric dipole domains and improved long range order.