Defect Structure of Zinc-Doped LiNbO3 Crystals in a Wide Range of Dopant Concentrations

IR absorption spectra of zinc-doped LiNbO3 crystals in the stretching region of OH groups, Raman spectra of the crystals, and their optical absorption spectra provide evidence of drastic changes in the mechanism responsible for the incorporation of Zn into the structure of the crystals and the nature of hydrogen bonds and the corresponding proton-containing charged defect complexes ( $$V_{{{\text{Li}}}}^{ - }$$ –OH–, NbLi–OH−, and $${\text{Zn}}_{{{\text{Nb}}}}^{{{\text{3}} - }}$$ –OH−) near a concentration threshold at ≈6.76 mol % ZnO in the melt.