Boron Influence on Defect Structure and Properties of Lithium Niobate Crystals

Crystals

NataliaA. Teplyakova¹  NikolayV. Sidorov¹  IrinaV. Birukova¹  OlgaV. Makarova¹  RomanA. Titov¹  DianaV. Manukovskaya¹  MikhailN. Palatnikov¹ 

[1] Tananaev Institute of Chemistry–Subdivision of the Federal Research Centre “Kola Science Centre of the Russian Academy of Sciences”, 26 a, Akademgorodok, 184209 Apatity, Murmansk region, Russia;

关键词: lithium niobate;    doping;    melt;    Raman spectroscopy;    photoinduced light scattering;    photoelectric fields;   

DOI  :  10.3390/cryst11050458

来源: DOAJ

【 摘 要 】

Defect structure of nominally pure lithium niobate crystals grown from a boron doped charge have been studied by Raman and optical spectroscopy, laser conoscopy, and photoinduced light scattering. An influence of boron dopant on optical uniformity, photoelectrical fields values, and band gap have been also studied by these methods in LiNbO₃ crystals. Despite a high concentration of boron in the charge (up to 2 mol%), content in the crystal does not exceed 10⁻⁴ wt%. We have calculated that boron incorporates only into tetrahedral voids of crystal structure as a part of groups [BO₃]³⁻, which changes O–O bonds lengths in O₆ octahedra. At this oxygen–metal clusters MeO₆ (Me: Li, Nb) change their polarizability. The clusters determine optically nonlinear and ferroelectric properties of a crystal. Chemical interactions in the system Li₂O–Nb₂O₅–B₂O₃ have been considered. Boron, being an active element, structures lithium niobate melt, which significantly influences defect structure and physical properties of a crystal grown from such a melt. At the same time, amount of defects Nb_Li and concentration of OH groups in LiNbO₃:B is close to that in stoichiometric crystals; photorefractive effect, optical, and compositional uniformity on the contrary is higher.

【 授权许可】

Unknown