CHARACTERISTICS OF MGO-DOPED LINBO3 CRYSTALS

Congruent MgO:LiNbO3 (MLN) single crystals doped with 0, 2.5, 5.0, 7.5 and 10.0 mol% of MgO contents were grown by the Czochralski method. T he grown crystals were water clear without any precipitation. The dens ity and Curie temperature (T-C) for MLN crystals were measured. The Cu rie temperature increased first with the MgO concentration and decreas ed again when the concentration of MgO went beyond the threshold limit ([Mg](C), 5.0-7.5 mol%). We also measured optical absorption edge and IR absorption spectra at room temperature for MLN crystals. The thres hold concentration of nearly 5.0 mol% was estimated. The IR absorption peak appeared at 3470 cm(-1) in 0-5.0 mol% and at 3534 cm(-1) in 7.5- 10.0 mol%; the peak shifted about 60 cm(-1) toward the shorter wavelen gth side.