NMR Analysis of Mg Ion Localization in $LiNbO_{3}$ Crystal

The analysis of cation sublattices population in magnesium doped $LiNbO_{3}$ crystals is carried out. It is shown that volume concentration of lithium vacancies $(V_{Li})$ monotonously increases with increasing of MgO content in the crystal up to the threshold value. A series of $LiNbO_{3}$ crystals with various concentration of $Mg^{2+}$ were investigated by $\text{}^{7}Li$ and $\text{}^{93}Nb$ Nuclear Magnetic Resonance (NMR). It is concluded that the peculiarities of NMR spectra in Mg-doped $LiNbO_{3}$ crystals can be explained by the formation of defect complexes including $Mg_{Li}$ ions and $V_{Li}$ on the shortest distances between them.