Domain Structure Formation By Electron Beam Irradiation In Lithium Niobate Crystals At Elevated Temperatures

We have studied experimentally the domain formation by electron beam irradiation in congruent lithium niobate crystals covered by a photoresist layer at the elevated temperatures up to 200 degrees C. The measured linear dose dependence of the switched domain area created by isolated dot irradiation has been attributed to external screening of the depolarization field by charges produced by incoming electrons. The significant decrease in the threshold field at the elevated temperatures has led to an increase in the domain area. The observed qualitative change of the domain shape with the temperature increase has been attributed to the highly nonequilibrium switching conditions caused by the existence of the artificial dielectric layer and domination of the stochastic nucleation. The optimal values of temperature and dose have allowed obtaining almost flat boundary of the switched area for line irradiation. The periodically poled structures of the through domains with periods from 10 to 40 mu m have been created. Published under license by AIP Publishing.