Domain formation in heavily doped LiNbO3:Mg crystals exposed to an electron beam

This paper presents a detailed study of domain structures produced by an electron beam on the Z-cut surface of LiNbO3:Mg crystals. The doping level and procedure have been shown to influence the shape and number of domains formed in the electron charge deposition zone on the crystal surface. Controlled formation of domains and domain structures through electron beam writing has only been achieved in samples with subthreshold magnesium concentration and in LiNbO3:Mg,Fe samples. The experimental results obtained are discussed in terms of differences in the defect structure and mechanisms of electronic conduction of the samples.