scholarly journals Distribution of point defects in lithium niobate and defect-dependent electromechanical coupling

2017 ◽  
Author(s):  
Chandrima Chatterjee ◽  
Igor Ostrovskii
Keyword(s):  
Lithium Niobate ◽  
Point Defects ◽  
Electromechanical Coupling

scholarly journals In-Situ Process and Simulation of High-Performance Piezoelectric-on-Silicon Substrate for SAW Sensor

2021 ◽  
Vol 8 ◽  
Author(s):  
Rui Ma ◽  
Weiguo Liu ◽  
Xueping Sun ◽  
Shun Zhou
Keyword(s):  
Thin Film ◽  
Lithium Niobate ◽  
High Performance ◽  
Electromechanical Coupling ◽  
Substrate Material ◽  
Electromechanical Coupling Coefficient ◽  
Bonding Layer ◽  
Saw Sensor ◽  
Rayleigh Mode

This paper studied the manufacturing process of Piezoelectric-on-Silicon (POS) substrate which integrates 128° Y–X Lithium niobate thin film and silicon wafer using Smart-Cut technology. The blistering and exfoliation processes of the He as-implanted LN crystal under different annealing temperatures are observed by the in-situ method. Unlike the conventional polishing process, the stripping mechanism of the Lithium niobate thin film is changed by controlling annealing temperature, which can improve the surface morphology of the peeling lithium niobate thin film. We prepared the 128° Y–X POS substrate with high single-crystal Lithium niobate thin film and surface roughness of 3.91 nm through Benzocyclobutene bonding. After simulating the surface acoustic wave (SAW) characteristics of the POS substrate, the results demonstrate that the Benzocyclobutene layer not only performs as a bonding layer but also can couple more vibrations into the LN thin film. The electromechanical coupling coefficient of the POS substrate is up to 7.59% in the Rayleigh mode when hLN/λ is 0.3 and hBCB/λ is 0.1. Therefore, as a high-performance substrate material, the POS substrate has proved to be an efficient method to miniaturize and integrate the SAW sensor.

Nonuniform electromechanical efficiency and point defects in lithium niobate

2017 ◽  
Vol 142 (4) ◽  
pp. 2722-2722
Author(s):  
Chandrima Chatterjee ◽  
Igor Ostrovskii
Keyword(s):  
Lithium Niobate ◽  
Point Defects

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.

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