Effect of the structure and mechanical properties of the near-surface layer of lithium niobate single crystals on the manufacture of integrated optic circuits

2017 ◽  
Vol 53 (1) ◽  
pp. 82-87 ◽  
Author(s):  
A. V. Sosunov ◽  
R. S. Ponomarev ◽  
V. A. Yur’ev ◽  
A. B. Volyntsev
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Lithium Niobate ◽  
Single Crystals ◽  
Near Surface

Deepening of domains at e-beam writing on the -Z surface of lithium niobate

2021 ◽  
Author(s):  
Lyudmila Kokhanchik ◽  
Evgenii Emelin ◽  
Vadim Vladimirovch Sirotkin ◽  
Alexander Svintsov
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Lithium Niobate ◽  
Electric Field ◽  
Domain Walls ◽  
Normal Component ◽  
Beam Current ◽  
Near Surface ◽  
Domain Structures ◽  
Sign Inversion

Abstract The focus of the study was to investigate the peculiarities of the domains created by electron beam (e-beam) in a surface layer of congruent lithium niobate, which comparable to a depth of electron beam charge penetration. Direct e-beam writing (DEBW) of different domain structures with a scanning electron microscope was performed on the polar -Z cut. Accelerating voltage 15 kV and e-beam current 100 pA were applied. Different patterns of local irradiated squares were used to create domain structures and single domains. No domain contrast was observed by the PFM technique. Based on chemical etching, it was found that the vertices of the domains created do not reach the surface level. The average deepening of the domain vertices was several hundred nanometers and varied depending on the irradiation dose and the location of the irradiated areas (squares) relative to each other. Computer simulation was applied to analyze the spatial distribution of the electric field in the various irradiated patterns. The deepening was explained by the fact that in the near-surface layer there is a sign inversion of the normal component of the electric field strength vector, which controls the domain formation during DEBW. Thus, with the help of e-beam, domains were created completely located in the bulk, in contrast to the domains that are nucleated on the surface of the -Z cut during the polarization inversion with AFM tip. The detected deepening of e-beam domains suggests the possibility of creating the “head-to-head” domain walls in the near-surface layer lithium niobate by DEBW.

Мicro-Optical Structures Written by Photothermal Method in a Specially Modified Near-Surface Layer of Lithium Niobate Crystals

2019 ◽  
Vol 62 (4) ◽  
pp. 732-734
Author(s):  
P. P. Basnin ◽  
I. M. Chirkova ◽  
E. P. Kokanyan ◽  
S. M. Kostritskii ◽  
O. G. Sevostyanov
Keyword(s):  
Surface Layer ◽  
Lithium Niobate ◽  
Near Surface ◽  
Photothermal Method ◽  
Lithium Niobate Crystals

Surface Treatment of Materials with High Current Pulsed Electron Beam

2005 ◽  
Vol 475-479 ◽  
pp. 3959-3962 ◽  
Author(s):  
Sheng Zhi Hao ◽  
B. Gao ◽  
Ai Min Wu ◽  
Jian Xin Zou ◽  
Ying Qin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Electron Beam ◽  
Surface Treatment ◽  
Short Pulse ◽  
Research Work ◽  
High Current ◽  
Near Surface ◽  
Pulsed Electron Beam ◽  
Dynamic Stress Field

High current pulsed electron beam (HCPEB) is now becoming a promising energetic source for the surface treatment of materials. When the concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress field induced by an abrupt thermal distribution in the interactive zone impart surface layer with improved physicochemical and mechanical properties. The present paper reports mainly our experimental research work on this new-style technique. Investigations performed with a variety of constructional materials (aluminum, carbon and mold steel, magnesium alloys) have shown that the most pronounced changes of composition, microstructure and properties occur in the near-surface layers, while the thickness of the modified layer with improved mechanical properties (several hundreds of micrometers) is significantly greater than that of the heat-affected zone due to the propagation of stress wave. The surfaces treated with either simply several pulses of bombardment or complex techniques, such as rapid alloying by HCPEB can exhibit improved mechanical and physicochemical properties to some extent.

scholarly journals ELECTRIC CRYSTALLIZATION OF THIN FILMS OF SODIUM - TUNGSTEN BRONZE

2020 ◽  
pp. 213-221
Author(s):  
Борис Магометович Хуболов
Keyword(s):  
Thin Films ◽  
Surface Layer ◽  
Single Crystals ◽  
Nuclear Reactions ◽  
Tungsten Bronze ◽  
Amorphous Structure ◽  
Near Surface ◽  
Sodium Tungsten ◽  
Depletion Depth ◽  
Sodium Tungsten Bronze

В работе рассмотрены вопросы получения тонких пленок натрийвольфрамовых бронз кубической структуры методом электрокристаллизации. Приведены основные параметры полученных пленок. Сняты спектры отражения пленок для неокрашенных и окрашенных пленок. Исследование приповерхностного слоя монокристаллов натрий-вольфрамовых бронз методами протонографии и ядерных реакций показало их высокое структурное совершенство. Анодная и катодная поляризации монокристаллов приводят к изменению структуры их приповерхностного слоя. Обеднение по натрию приповерхностного слоя присутствует и при катодной и при анодной поляризации, и глубина обеднения растет с ростом времени поляризации величины напряжения. Электронографией исследованы тонкие пленки натрийвольфрамовых бронз, установлена аморфная структура свеженапыленных пленок для всех температур подложки. Отжиг электронным лучом приводит к кристаллизации пленок. The paper considers the problems of obtaining thin films of sodium-tungsten bronzes of a cubic structure by the method of electrocrystallization. The main parameters of the obtained films are presented. The reflection spectra of the films were recorded for uncolored and colored films. Investigation of the near-surface layer of sodium-tungsten bronze single crystals by protonography and nuclear reactions showed their high structural perfection. The anodic and cathodic polarizations of single crystals lead to a change in the structure of their surface layer. Depletion in sodium of the nearsurface layer is present at both cathodic and anodic polarization, and the depletion depth increases with increasing polarization time of the voltage value. Thin films of sodium-tungsten bronzes have been investigated by electron diffraction, and the amorphous structure of freshly deposited films has been established for all substrate temperatures. Annealing with an electron beam leads to crystallization of the films.

scholarly journals The Effect of Heat Treatment on the Microstructure and Mechanical Properties of 2D Nanostructured Au/NiFe System

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1077 ◽  
Author(s):  
Tatiana Zubar ◽  
Valery Fedosyuk ◽  
Daria Tishkevich ◽  
Oleg Kanafyev ◽  
Ksenia Astapovich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Surface Layer ◽  
Near Surface ◽  
Force Microscopy ◽  
Thermally Activated ◽  
Atomic Force ◽  
Microstructure And Mechanical Properties ◽  
Internal Volume ◽  
Increasing Temperature

Nanostructured NiFe film was obtained on silicon with a thin gold sublayer via pulsed electrodeposition and annealed at a temperature from 100 to 400 °C in order to study the effect of heat treatment on the surface microstructure and mechanical properties. High-resolution atomic force microscopy made it possible to trace stepwise evolving microstructure under the influence of heat treatment. It was found that NiFe film grains undergo coalescence twice—at ~100 and ~300 °C—in the process of a gradual increase in grain size. The mechanical properties of the Au/NiFe nanostructured system have been investigated by nanoindentation at two various indentation depths, 10 and 50 nm. The results showed the opposite effect of heat treatment on the mechanical properties in the near-surface layer and in the material volume. Surface homogenization in combination with oxidation activation leads to abnormal strengthening and hardening-up of the near-surface layer. At the same time, a nonlinear decrease in hardness and Young’s modulus with increasing temperature of heat treatment characterizes the internal volume of nanostructured NiFe. An explanation of this phenomenon was found in the complex effect of changing the ratio of grain volume/grain boundaries and increasing the concentration of thermally activated diffuse gold atoms from the sublayer to the NiFe film.

scholarly journals Investigation of near-surface layer dislocation density of lithium niobate single crystal wafers using chemical etching

2021 ◽  
Vol 2086 (1) ◽  
pp. 012031
Author(s):  
R S Ponomarev ◽  
A V Sosunov ◽  
O R Semenova ◽  
N P Prokhorov ◽  
M Kuneva
Keyword(s):  
Surface Layer ◽  
Diffusion Coefficient ◽  
Dislocation Density ◽  
Lithium Niobate ◽  
Single Crystal ◽  
Chemical Etching ◽  
Proton Exchange ◽  
Optical Modulators ◽  
Near Surface ◽  
Lithium Niobate Single Crystal

Abstract Using chemical etching it was shown that the density of dislocation in lithium niobate (LN) single crystal wafers is higher near the surface in depth about 20 um than in the depth of crystal. It caused to change of diffusion coefficient during the waveguide formation with proton exchange (PE) method and can increase DC-drift of intensity optical modulators based on PE-waveguides.

The Influence of Ion Implantation on The Near-Surface Mechanical Properties of Ceramics

1990 ◽  
Vol 188 ◽  
Author(s):  
C. J. McHargue ◽  
M. E. O'Hern ◽  
D. L. Joslin
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Surface Layer ◽  
Elastic Modulus ◽  
Ion Implantation ◽  
Crystalline Material ◽  
Specific Structure ◽  
Near Surface ◽  
Crystalline Surface ◽  
Amorphous Surface

ABSTRACTIon implantation of ceramics such as Al2O3 and SiC may produce a highly damaged but crystalline surface layer or an amorphous surface. The specific structure depends upon the implantation parameters. Studies using microindentation techniques show that a crystalline implanted surface has a higher hardness (by 10 to 50%) than the corresponding unimplanted crystal but the elastic modulus is essentially unchanged. The hardness and elastic modulus of amorphous implanted surfaces are less than those of the crystalline material. Estimates of the residual stress have been obtained from microindentation tests.

scholarly journals Reduction of drift of operating point in lithium niobate-based integrated-optical circuit

2021 ◽  
pp. 5-13
Author(s):  
Alexey V. Sosunov ◽  
◽  
Roman S. Ponomarev ◽  
Anton A. Zhuravlev ◽  
Sergey S. Mushinsky ◽  
...  
Keyword(s):  
Surface Layer ◽  
Lithium Niobate ◽  
Lithium Niobate Crystal ◽  
Proton Exchange ◽  
Operating Point ◽  
Near Surface ◽  
Optical Output ◽  
Integrated Optical ◽  
Optical Circuits ◽  
Integrated Optical Circuits

This work is devoted to the study of the drift of the operating point of integrated-optical circuits based on proton-exchange waveguides in lithium niobate crystal with a recovered structure of the near-surface layer. Recovered of the damaged near-surface layer of lithium niobate wafer was carried out using pre-annealing at temperature of 500 °C. Drift of operating point is characterized by a constant change in the optical output power of the integrated-optical circuits when a bias voltage is applied to the electrodes or temperature changes. Recovered of the damaged near-surface layer of lithium niobate wafer leads to a decrease in the short-term and long-term drifts of the operating point of integrated-optical circuits. Crystal structure factor was investigated on the drift of operating point of integrated-optical circuits based on lithium niobate crystal.

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