Defect chemistry analysis of the defect structure in Mg-doped LiNbO3 crystals

Abstract

On the basis of the Li vacancy model of intrinsic defects in LiNb03 crystal, the defect structure formed in LiNbO3:Mg varying with the Mg content are proposed. The Liz0 and NbzOs contents, the Li/Nb ratio in the crystal, and the density of the crystal are calculated by using the defect structure. The calculated values are in good agreement with the reported experimental results.

Growth, defect structure, and THz application of stoichiometric lithium niobate

“…The defect chemistry of LN crystals based on the preferred Li vacancy model 42 will be detailed in Section III, where the impact of ODR ions in suppressing the antisite Nb Li defects will also be discussed. As follows from the analysis, the critical threshold concentrations of the ODR dopants depend both on the actual Li/Nb ratio and the valence of the built-in dopant.…”

“…Models describing the incorporation of Mg ions 42,[70][71][72] usually assume that Mg ions compete for Li sites with antisite Nb Li ions up to the threshold concentration where all antisites are eliminated, while above the threshold, Mg ions replace both Li and Nb ions in the lattice. The main differences in the models are the specific reaction formulas describing the incorporation mechanism in the successive stages.…”

“…For this calculation, the antisite niobium concentration (c Nb Li ) was determined as a function of x and c Mg using the model of Liu et al 42 The UV-edge shift due to this c Nb Li was calculated using Eq. (3.1) and subtracted from the experimental UV-edge position.…”

NMR Analysis of Mg Ion Localization in LiNbO3Crystal

“…In the number of articles devoted to study of magnesium localization in LN crystals [13][14][15], experimentally obtained dependences of Li/Nb ratio (R) in the crystal (R = x/z) on MgO molar content (k) are presented. It is obvious that k value can be written as k = y 0.5(x+z)+y .…”

“…It is obvious that k value can be written as k = y 0.5(x+z)+y . Taking into account a condition of electroneutrality of the crystal it is possible to define the population of structural positions in cation sublattices (1), (2) we used the data presented in [13][14][15]. The results of these calculations are shown in Fig.…”