STUDY ON PERIODICAL POLARIZATION CHARACTERISTICS OF NEAR-STOICHIOMETRIC MgO-DOPED LiNbO3 CRYSTAL
近化学计量比掺镁铌酸锂晶体周期极化特性研究

The fine near-stoichioment MgO-doped LiNbO 3 crystals were fabricated by the vapor transport equilibration and the dependence of the switch field on / ratio was systematically investigated. The results show that the switch field for 180° ferroelectric domain reversal in the near-stoichioment Mg:LiNbO 3 crystal decreases as / ratio incrwases. 180° domain reversal in the 1.0mm near-stoichiometric Mg:LiNbO 3 samples is successfully achieved by using 3.5kV/mm switch field. A reasonable explanation for experimental results is given, which is based on the Li-site vacancy point defect model.