Features of the Defect Structure and Luminescence of Nominally Pure Lithium Niobate Crystals Produced Using Different Technologies
Maxim Smirnov,
Diana Manukovskaya,
Nikolay Sidorov,
Mikhail Palatnikov
Affiliations
Maxim Smirnov
Tananaev Institute of Chemistry—Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT), 184209 Apatity, Russia
Diana Manukovskaya
Tananaev Institute of Chemistry—Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT), 184209 Apatity, Russia
Nikolay Sidorov
Tananaev Institute of Chemistry—Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT), 184209 Apatity, Russia
Mikhail Palatnikov
Tananaev Institute of Chemistry—Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences” (ICT), 184209 Apatity, Russia
We have established that luminescence in lithium niobate crystals both congruent and near-stoichiometric (R ≈ 1) is due to point defects in the cationic sublattice and intraconfigurational transitions in the oxygen-octahedral NbO6 clusters. We have also determined that the main contribution to the luminescence in the visible and near IR regions is made by luminescence centers with the participation of NbLi defects: the NbLi-NbNb bipolaron pair and the NbLi-O defect in a congruent crystal. The minimum intensity of bipolaron luminescence has been observed in stoichiometric crystals obtained using different technologies. Weak luminescence of the NbLi-NbNb bipolaron pair indicates a small number of NbLi defects in the crystal structure. The number of NbLi defects in the crystal structure indicates a deviation of the crystal composition from stoichiometry.
