Structural Features of Nominally Pure Lithium Niobate Crystals Grown from Boron-Doped Charge

2020 ◽  
Vol 312 ◽  
pp. 128-133
Author(s):  
Nikolay Sidorov ◽  
Roman Titov ◽  
Natalya A. Teplyakova ◽  
Mikhail Palatnikov ◽  
Alexander Vjacheslavovich Syuy
Keyword(s):  
Crystal Structure ◽  
Lithium Niobate ◽  
Single Crystals ◽  
Czochralski Method ◽  
Structural Features ◽  
Structural Defects ◽  
Cation Sublattice ◽  
Structural Units ◽  
Boron Doped ◽  
Lithium Niobate Crystals

The features of the structure of single crystals LiNbO3:B3+ (0.12 and 0.18 wt %) grown by the Czochralski method from the mixture of different genesis were studied. It was found that boron is able to incorporate into the crystal structure of lithium niobate in a trace amounts (~ 10–4–10–5 wt %), decreasing the concentration of structural defects NbLi. Thus, ordering of structural units of the cation sublattice of lithium niobate crystals grown from a congruent composition melt approach in that of stoichiometric crystals.

scholarly journals Structural particularities and optical properties of lithium niobate single crystals grown from the charge doped by boron.

2020 ◽  
Vol 11 (3-2020) ◽  
pp. 189-195
Author(s):  
R. A. Titov ◽  
◽  
N. V. Sidorov ◽  
N. A. Teplyakova ◽  
M. N. Palatnikov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Lithium Niobate ◽  
Distribution Coefficient ◽  
Single Crystals ◽  
Infrared Absorption ◽  
Cation Sublattice ◽  
Structural Units ◽  
Photoinduced Light Scattering ◽  
Laser Conoscopy

The analysis of structural particularities and optical properties of LiNbO3 : B (0,55, 0,69 and 0,83 mol. % B2O3) was performed by methods of Raman and photoinduced light scattering, infrared absorption and laser conoscopy. It has been established that the boron impurity brings to 1 the distribution coefficient of lithium and niobium in the growing process. Thus, LiNbO3: B crystals grown from a congruent melt approach the stoichiometric crystals in ordering the structural units of the cation sublattice and the Li / Nb ratio.

scholarly journals Boron Influence on Defect Structure and Properties of Lithium Niobate Crystals

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 458
Author(s):  
Nikolay V. Sidorov ◽  
Natalia A. Teplyakova ◽  
Olga V. Makarova ◽  
Mikhail N. Palatnikov ◽  
Roman A. Titov ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Defect Structure ◽  
Photorefractive Effect ◽  
Ferroelectric Properties ◽  
High Concentration ◽  
Oh Groups ◽  
Boron Doped ◽  
Compositional Uniformity ◽  
Boron Dopant ◽  
Lithium Niobate Crystals

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 NbLi 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.

Fine Particularities of Structure and Optical Properties of Lithium Niobate Crystals Grown from Boron Doped Charge with Different Genesis

2019 ◽  
pp. 277-292
Author(s):  
Nikolay V. Sidorov ◽  
Natalya A. Teplyakova ◽  
Roman A. Titov ◽  
Mikhail N. Palatnikov ◽  
Alexander V. Syuy ◽  
...  
Keyword(s):  
Optical Properties ◽  
Lithium Niobate ◽  
Boron Doped ◽  
Lithium Niobate Crystals

scholarly journals CALCULATION OF THE POINT DEFECT CONCENTRATION OF THE CATION SUBLATTICE AND HYDROXYL GROUPS IN LITHIUM NIOBATE CRYSTALS OF DIFFERENT COMPOSITION

2020 ◽  
pp. 200-205
Author(s):  
Наталья Александровна Теплякова ◽  
Николай Васильевич Сидоров ◽  
Михаил Николаевич Палатников
Keyword(s):  
Phase Diagram ◽  
Lithium Niobate ◽  
Point Defects ◽  
Cation Sublattice ◽  
Hydroxyl Groups ◽  
Ir Absorption ◽  
Oh Groups ◽  
Ir Absorption Spectra ◽  
Stretching Vibrations ◽  
Lithium Niobate Crystals

Исследованы ИК-спектры поглощения в области валентных колебаний OH - групп кристаллов ниобата лития стехиометрического и конгруэнтного составов. Рассчитана концентрация OH - групп, отношение Li / Nb, а также концентрация точечных дефектов Nb и V. Результаты расчетов совпадают с литературными данными и подтверждаются фазовой диаграммой ниобата лития. Показано, что увеличение количества свободных протонов (вносящих вклад в проводимость) может обуславливать более высокие электропроводность, скорость термической фиксации голограмм и снижение эффекта фоторефракции. The IR absorption spectra in the region of stretching vibrations of OH - groups of lithium niobate crystals of stoichiometric and congruent compositions are studied. The results of calculations of the OH - groups concentration, the Li / Nb ratio and the concentration of point defects Nb and V coincide with the literature data. The phase diagram of lithium niobate confirms these results. It is shown that an increase in the number of free protons that contribute to conductivity can lead to reducing the optical damage and higher electrical conductivity and the rate of thermal fixation of holograms.

scholarly journals Enhancement of Photorefraction in Vanadium-Doped Lithium Niobate through Iron and Zirconium Co-Doping

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3143 ◽  
Author(s):  
Shahzad Saeed ◽  
Hongde Liu ◽  
Liyun Xue ◽  
Dahuai Zheng ◽  
Shiguo Liu ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Diffraction Efficiency ◽  
Czochralski Method ◽  
Fast Response ◽  
Holographic Storage ◽  
Co Doping ◽  
Dynamic Holography ◽  
Lithium Niobate Crystals ◽  
High Diffraction ◽  
Co Doped

A series of mono-, double-, and tri-doped LiNbO3 crystals with vanadium were grown by Czochralski method, and their photorefractive properties were investigated. The response time for 0.1 mol% vanadium, 4.0 mol% zirconium, and 0.03 wt.% iron co-doped lithium niobate crystal at 488 nm was shortened to 0.53 s, which is three orders of magnitude shorter than the mono-iron-doped lithium niobate, with a maintained high diffraction efficiency of 57% and an excellent sensitivity of 9.2 cm/J. The Ultraviolet-visible (UV-Vis) and OH− absorption spectra were studied for all crystals tested. The defect structure is discussed, and a defect energy level diagram is proposed. The results show that vanadium, zirconium, and iron co-doped lithium niobate crystals with fast response and a moderately large diffraction efficiency can become another good candidate material for 3D-holographic storage and dynamic holography applications.

Manifestation of the specific structural features of lithium niobate single crystals of different composition in their Raman spectra

2008 ◽  
Vol 105 (6) ◽  
pp. 913-918 ◽  
Author(s):  
P. G. Chufyrev ◽  
N. V. Sidorov ◽  
M. N. Palatnikov ◽  
A. A. Yanichev
Keyword(s):  
Lithium Niobate ◽  
Single Crystals ◽  
Raman Spectra ◽  
Structural Features

scholarly journals High-temperature poling treatment of congruent ferroelectric LiNb0.5Ta0.5O3 solid solution single crystals

2021 ◽  
Vol 7 (1) ◽  
pp. 17-20
Author(s):  
Anatolii A. Mololkin ◽  
Dmitry V. Roshchupkin ◽  
Eugenii V. Emelin ◽  
Rashid R. Fahrtdinov
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Lithium Niobate ◽  
Curie Temperature ◽  
Physical Properties ◽  
Single Crystals ◽  
Thermal Instability ◽  
Poling Process ◽  
Lithium Niobate Crystals ◽  
Piezoelectric Constants

Lithium niobate and tantalate are among the most important and widely used materials of acoustooptics and acoustoelectronics. They have high piezoelectric constants enabling their use as actuators. Their use is however restricted by the thermal instability of lithium niobate crystals and the low Curie temperature TC of lithium tantalate crystals. Overcoming these drawbacks typical of some compounds is possible by growing LiNb1-xTaxO3 single crystals. Good quality LiNb1-xTaxO3 single crystals have been grown using the Czochralsky technique. High-temperature poling process of LiNb1-xTaxO3 single crystals has been studied. The main differences between the process modes required for poling of congruent LiNb1-xTaxO3 single crystals and congruent LiNbO3 single crystals have been demonstrated. Parameters of high-temperature electric diffusion processing of LiNb1-xTaxO3 single crystals that provide for singledomain crystals for further study of physical properties have been reported.

scholarly journals A NEW METHOD OF THE STOICHIOMETRY INCREASE OF THE LITHIUM NIOBATE NONLINEAR-OPTICAL CRYSTAL

2021 ◽  
Vol 13 (2-2021) ◽  
pp. 16-28
Author(s):  
R.A. Titov ◽  
◽  
N.V. Sidorov ◽  
N.A. Teplyakova ◽  
V.M. Voskresenskiy ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Nonlinear Optical ◽  
Ferroelectric Properties ◽  
Theoretical Data ◽  
Structural Features ◽  
Distribution Coefficients ◽  
Complexing Agent ◽  
Cation Sublattice ◽  
Octahedral Cluster ◽  
Gibbs Energies

Experimental and theoretical data on the influence of В2О3 flux on the crystal-melt system, the structural features, and the optical properties of a crystal of lithium niobate are summarized. The Gibbs energies of the borate impurities formation (Al4B2O9, CaB2O4, CaB4O7, Ca2B2O5, Ca3B2O6, PbB2O4) in a congruent composition charge of lithium niobate are calculated. It was found that the element boron, as an active complexing agent, in the composition of the В2О3 flux aligns the distribution coefficients of lithium (KLi) and niobium (KNb). Also, the element boron is able to prevent the transition of trace amounts of impurity metals into the structure of a lithium niobate crystal. Boron increases the ordering of structural units of the cation sublattice and distorts the anionic framework of the crystal. This is due to the fact that boron is embedded in the tetrahedral voids faces of the crystal structure in trace amounts (4∙10-4 mol.%). This leads to changes in bond lengths O-O of the oxygen octahedra O6, thereby changing polarizability oxygen-octahedral cluster NbO6, determining nonlinear optical and ferroelectric properties of the crystal.

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