This paper reports a comparative study of the homogeneity of LiNbO3〈Mg〉 (≥5 mol % Mg) crystals grown from a charge synthesized using Nb2O5〈Mg〉 prepared through homogeneous magnesium doping of a...

Methods for direct doping of niobium pentoxide with photovoltaically inactive Mg²⁺ and Gd³⁺ cations were developed for subsequent use in the synthesis of a stock for growing single crystals of lithium niobate with improved optical characteristics. The Raman spectra of doped pentoxides Nb₂O₅: Mg and Nb₂O₅: Gd revealed their island structures.

Double-doping technology for growing lithium niobate crystals (LiNbO₃:Mg:Zn) was developed. The crystals were highly homogeneous and had high optical damage resistance, so they show promise for use as photonic and nonlinear optical components. The crystals were grown from the LiNbO₃:0.145 wt % Mg:1.98 wt % Zn batch. The batch was prepared by homogeneous doping. The proposed flowsheet can serve as the basis for a large-scale technology of doped lithium niobate single crystals.

We investigated how the type of an extraction system affects the characteristics of precursors Nb₂O₅:Mg produced at the stage of extraction processing of niobium-containing HF-H₂SO₄ and HF-HCl solutions with an extractant comprising a mixture of dimethylamides of carboxylic acids of the C₁₀–C₁₃ fraction and 1-octanol in Escaid diluent. We also studied the optical properties of homogeneously doped crystals LiNbO₃:Mg grown from a batch synthesized with the use of pentoxide Nb₂O₅:Mg obtained from various extraction systems. On Z-cut LiNbO₃:Mg crystal wafers, such mechanical characteristics as Young’s modulus and microgravity were measured.

This paper reports a process for the growth of optically homogeneous lithium niobate single crystals containing boron as a dopant. A LiNbO₃:B crystal has been grown by the Czochralski technique using a single-phase growth charge synthesized from a Nb₂O₅:B precursor and lithium carbonate. We have assessed the optical quality of the crystal by a high-speed method from the number of scattering centers, evaluated its single-domain state by piezoacoustic measurements, and calculated its d₃₃₃ piezoelectric modulus component. The results demonstrate that the crystal has a high degree of optical uniformity and is single-domain. The proposed method for LiNbO₃:B crystal growth can serve as a basis of a commercial-scale process for the preparation of doped lithium niobate single crystals for various engineering applications.