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 8.3 mol % were grown by the Czochralski technique. The effects of incorporating Zn2+ ions into LiNb O3 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 NbLi 4- +4 VLi-. However, the coercive field of Zn-doped ions into LiNb O3 is insensitive to the ZnLi 2+ + VLi-. Experimental results indicate that four distinct substitutions of Zn-2 ions incorporated into ions into LiNb O3 crystals for doping concentrations from 0 to 8.3 mol %. The extent of Zn substitution is quantitatively determined for doping of below 7.5 mol %.