PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING

Lithium niobate crystals are widely used in the manufacturing of integrated optical phase and intensity modulators. The production method is based on the formation of optical waveguides in the surface layers of LiNbO3 by means of proton exchange. Subsequent annealing of proton-exchanged structures...

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Main Authors: Igor V. Petukhov, Sergey S. Myshinsky, Mariya A. Permyakova, Vladimir I. Kichigin, Ljudmila N. Malinina, Anatoliy B. Volyntsev
Format: Article
Language:English
Published: Voronezh State University 2018-09-01
Series:Конденсированные среды и межфазные границы
Subjects:
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author Igor V. Petukhov
Sergey S. Myshinsky
Mariya A. Permyakova
Vladimir I. Kichigin
Ljudmila N. Malinina
Anatoliy B. Volyntsev
author_facet Igor V. Petukhov
Sergey S. Myshinsky
Mariya A. Permyakova
Vladimir I. Kichigin
Ljudmila N. Malinina
Anatoliy B. Volyntsev
author_sort Igor V. Petukhov
collection DOAJ
description Lithium niobate crystals are widely used in the manufacturing of integrated optical phase and intensity modulators. The production method is based on the formation of optical waveguides in the surface layers of LiNbO3 by means of proton exchange. Subsequent annealing of proton-exchanged structures is usually performed in order to obtain stable and low-loss waveguides. The aim of this paper is to study phase transitions in the surface layer of proton-exchanged waveguides on Z-cuts of lithium niobate crystals during annealing. In our research, the following methods were used: polarized light optical microscopy (bright fi eld and dark fi eld), mode spectroscopy (determination of the refractive index profi le), IR-spectroscopy, and XRD (θ/2θ curves). Congruent lithium niobate (Sipat) was used as a material. Proton exchange was carried out in molten benzoic acid at 190 °С for 2 hours.The samples were then annealed at 1-hour intervals at 330 °С. The total duration of annealing was 18 hours. The sequence of the phase transformations at annealing proton-exchange layers on Z-cut lithium niobate crystals is similar to that on X cut: β1, β2-phase →κ2-phase→κ1-phase → α-phase. The difference is that κ1-phase particles are not formed during annealing and the coherence of the layers of different phases is not disturbed. This results from a lesser magnitude of strains in proton-exchange phases on Z cut LiNbO3 as compared to X cut.
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spelling doaj.art-cf3c491fecc5499e9c8ae0797e0e17332022-12-22T00:44:05ZengVoronezh State UniversityКонденсированные среды и межфазные границы1606-867X1606-867X2018-09-0120344345110.17308/kcmf.2018.20/581PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALINGIgor V. Petukhov0Sergey S. Myshinsky1Mariya A. Permyakova2Vladimir I. Kichigin3Ljudmila N. Malinina4Anatoliy B. Volyntsev5Cand. Sci. (Chem.), Associate Professor, Department of Physical Chemistry; Perm State UniversityEngineer, Perm State Universitygraduate student, Department of Physical Chemistry, Perm State UniversityCand. Sci. (Chem.), Senior Researcher, Department of Physical Chemistry, Perm State UniversityEngineer of Solid State Physics Department, Perm State UniversityDr. Sci. (Phys.-Math.), Professor, Head of Solid State Physics Department, Perm State UniversityLithium niobate crystals are widely used in the manufacturing of integrated optical phase and intensity modulators. The production method is based on the formation of optical waveguides in the surface layers of LiNbO3 by means of proton exchange. Subsequent annealing of proton-exchanged structures is usually performed in order to obtain stable and low-loss waveguides. The aim of this paper is to study phase transitions in the surface layer of proton-exchanged waveguides on Z-cuts of lithium niobate crystals during annealing. In our research, the following methods were used: polarized light optical microscopy (bright fi eld and dark fi eld), mode spectroscopy (determination of the refractive index profi le), IR-spectroscopy, and XRD (θ/2θ curves). Congruent lithium niobate (Sipat) was used as a material. Proton exchange was carried out in molten benzoic acid at 190 °С for 2 hours.The samples were then annealed at 1-hour intervals at 330 °С. The total duration of annealing was 18 hours. The sequence of the phase transformations at annealing proton-exchange layers on Z-cut lithium niobate crystals is similar to that on X cut: β1, β2-phase →κ2-phase→κ1-phase → α-phase. The difference is that κ1-phase particles are not formed during annealing and the coherence of the layers of different phases is not disturbed. This results from a lesser magnitude of strains in proton-exchange phases on Z cut LiNbO3 as compared to X cut.lithium niobateZ-cutproton exchangeannealingphase transformation.
spellingShingle Igor V. Petukhov
Sergey S. Myshinsky
Mariya A. Permyakova
Vladimir I. Kichigin
Ljudmila N. Malinina
Anatoliy B. Volyntsev
PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
Конденсированные среды и межфазные границы
lithium niobate
Z-cut
proton exchange
annealing
phase transformation.
title PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
title_full PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
title_fullStr PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
title_full_unstemmed PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
title_short PECULIARITIES OF STRUCTURAL PHASE TRANSFORMATIONS IN PROTON EXCHANGED LAYERS OF Z-CUT LITHIUM NIOBATE CRYSTAL DURING ANNEALING
title_sort peculiarities of structural phase transformations in proton exchanged layers of z cut lithium niobate crystal during annealing
topic lithium niobate
Z-cut
proton exchange
annealing
phase transformation.
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