Impact of a dopant impurity electronic structure on physical properties, defect structure, and features of lithium niobate doping technology

The macro- and microstructure of doped LiNbO$_{3}$ crystals is studied, their transmission spectra are investigated, and the effective coefficients characterizing the dopant impurity distribution are determined. We analyze the literature data on phase diagrams of the ternary system Li$_{2}$O–Nb$_{2}$O$_{5}$–dopant oxide and the electron configurations of dopant elements, and the results suggest that this can be used as a basis for designing technological conditions for growing doped lithium niobate crystals and predicting their quality. With $p$-elements (boron), structurally and compositionally uniform LiNbO$_{3}$ crystals can be grown, with the doping impurity not being incorporated in the crystal. $s$- and $d$-metals (magnesium and zinc) have a similar effect on the melt and properties of resulting LiNbO$_{3}$ crystals, which have periodic domain structures and similar types of point defects. Due to their electronic structure, $f$-metals (cerium) bring the melt to such a structure that this enables the formation of a periodic domain structure in LiNbO$_{3}$ crystals during their growth.