Open AccessОптические аномалии в кристаллах LiNbO-=SUB=-3-=/SUB=- : Mg
Author(s) -
N. V. Sidorov,
Л. А. Бобрева,
Н. А. Теплякова,
М. Н. Палатников,
О. В. Макарова
Publication year - 2019
Publication title -
žurnal tehničeskoj fiziki
Language(s) - English
Resource type - Journals
eISSN - 1726-748X
pISSN - 0044-4642
DOI - 10.21883/os.2019.09.48203.93-19
Subject(s) - absorption (acoustics) , magnesium , absorption edge , analytical chemistry (journal) , chemistry , materials science , crystallography , band gap , metallurgy , optoelectronics , chromatography , composite material
We have established that increase in magnesium concentration in LiNbO3:Mg(0.19-5.91 mol% MgO) crystals leads to re-structuring in defective structure and optical anomalies connected with the re-structuring. The anomalies have threshold character. Optical uniformity of crystals was shown to increase at Mg concentration close to a threshold one ~3.0 mol% MgO. IR-absorption spectrum in the area of stretching vibrations of OH groups shifts to a high-frequency area (~50 cm-1 in comparison with other crystals), when Mg concentration nears the second threshold. At this sharp decrease in protons amount and jump-like shift of an absorption edge in the shortwave region are also observed. The shift was shown to be caused by the fact that at 5.5 mol% MgO all point defects NbLi are substitutes by Mg cations and with an increase in Mg concentration, Mg cations occupy Li and Nb sites forming point defects MgLi and MgNb.