Defect structure and light-induced scattering of Zr-doped nearstoichiometric Mn:Fe:LiNbO_3 crystals grown by TSSG method

摘要

Near-stoichiometric Mn:Fe:LiNbO_3 crystals doped with various concentration of ZrO_2 were grown by top seed solution growth (TSSG) method in the air atmosphere. The Zr concentration in the crystal was determined by inductively coupled plasma optical emission spectrometer. The defect structures were analyzed by means of ultraviolet-visible and infrared transmittance spectra. The appearance of vibration peak at 3466 cm~(-1) in infrared spectra manifested that Li/Nb ratio in crystals approached to stoichiometric proportion. The fundamental absorption edge represented continuous red-shift which was discrepancy with congruent doped LiNbO_3 crystals showed that doping ions possessed different location mechanism. The light-induced scattering of the doped stoichiometric LiNbO_3 crystals were quantitatively scaled via incident exposure energy. The results demonstrated that Zr(2 mol%):Mn:Fe:LiNbO_3 crystal had the weakest light-induced scattering and the mechanism related to their defect structures was discussed.