Substitution mechanism of ZnO-doped lithium niobate crystal determined by powder x-ray diffraction and coercive field

ZnO-doped lithium niobate crystals with a doped concentration of up to 8.3mol% were grown by the Czochralski technique. The effects of incorporating Zn2+ ions into LiNbO3 crystals were studied by powder x-ray diffraction and taking polarization hysteresis loop measurements. When the Li-site vacancy model is adopted, the coercive fields obtained from the polarization reversal measurement depend strongly on the number of NbLi4−+4VLi−. However, the coercive field of Zn-doped ions into LiNbO3 is insensitive to the ZnLi2++VLi−. Experimental results indicate that four distinct substitutions of Zn−2 ions incorporated into ions into LiNbO3 crystals for doping concentrations from 0to8.3mol%. The extent of Zn substitution is quantitatively determined for doping of below 7.5mol%.