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Klenen J, Sauerwein F, Vittadello L, Kömpe K, Hreb V, Sydorchuk V, Yakhnevych U, Sugak D, Vasylechko L, Imlau M. Gap-Free Tuning of Second and Third Harmonic Generation in Mechanochemically Synthesized Nanocrystalline LiNb 1-xTa xO 3 (0 ≤ x ≤ 1) Studied with Nonlinear Diffuse Femtosecond-Pulse Reflectometry. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:317. [PMID: 38334588 PMCID: PMC10857201 DOI: 10.3390/nano14030317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/13/2024] [Accepted: 01/23/2024] [Indexed: 02/10/2024]
Abstract
The tuning of second (SHG) and third (THG) harmonic emission is studied in the model system LiNb 1-xTa xO 3 (0≤x≤1, LNT) between the established edge compositions lithium niobate (LiNbO 3, x=0, LN) and lithium tantalate (LiTaO 3, x=1, LT). Thus, the existence of optical nonlinearities of the second and third order is demonstrated in the ferroelectric solid solution system, and the question about the suitability of LNT in the field of nonlinear and quantum optics, in particular as a promising nonlinear optical material for frequency conversion with tunable composition, is addressed. For this purpose, harmonic generation is studied in nanosized crystallites of mechanochemically synthesized LNT using nonlinear diffuse reflectometry with wavelength-tunable fundamental femtosecond laser pulses from 1200 nm to 2000 nm. As a result, a gap-free harmonic emission is validated that accords with the theoretically expected energy relations, dependencies on intensity and wavelength, as well as spectral bandwidths for harmonic generation. The SHG/THG harmonic ratio ≫1 is characteristic of the ferroelectric bulk nature of the LNT nanocrystallites. We can conclude that LNT is particularly attractive for applications in nonlinear optics that benefit from the possibility of the composition-dependent control of mechanical, electrical, and/or optical properties.
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Affiliation(s)
- Jan Klenen
- Department of Mathematics/Informatics/Physics, Osnabrueck University, 49076 Osnabrueck, Germany
- Research Center for Cellular Nanoanalytics, Osnabrueck (CellNanOs), Osnabrueck University, 49076 Osnabrueck, Germany
| | - Felix Sauerwein
- Department of Mathematics/Informatics/Physics, Osnabrueck University, 49076 Osnabrueck, Germany
- Research Center for Cellular Nanoanalytics, Osnabrueck (CellNanOs), Osnabrueck University, 49076 Osnabrueck, Germany
| | - Laura Vittadello
- Department of Mathematics/Informatics/Physics, Osnabrueck University, 49076 Osnabrueck, Germany
- Research Center for Cellular Nanoanalytics, Osnabrueck (CellNanOs), Osnabrueck University, 49076 Osnabrueck, Germany
| | - Karsten Kömpe
- Research Center for Cellular Nanoanalytics, Osnabrueck (CellNanOs), Osnabrueck University, 49076 Osnabrueck, Germany
- Department of Biology/Chemistry, Osnabrueck University, 49076 Osnabrueck, Germany
| | - Vasyl Hreb
- Department of Semiconductor Electronics, Lviv Polytechnic National University, 79013 Lviv, Ukraine (L.V.)
| | - Volodymyr Sydorchuk
- Institute for Sorption and Problems of Endoecology, National Academy of Sciences of Ukraine, 13 Gen. Naumov St., 03164 Kyiv, Ukraine
| | - Uliana Yakhnevych
- Department of Semiconductor Electronics, Lviv Polytechnic National University, 79013 Lviv, Ukraine (L.V.)
| | - Dmytro Sugak
- Department of Semiconductor Electronics, Lviv Polytechnic National University, 79013 Lviv, Ukraine (L.V.)
- Scientific Research Company ‘Electron-Carat’, 79031 Lviv, Ukraine
| | - Leonid Vasylechko
- Department of Semiconductor Electronics, Lviv Polytechnic National University, 79013 Lviv, Ukraine (L.V.)
| | - Mirco Imlau
- Department of Mathematics/Informatics/Physics, Osnabrueck University, 49076 Osnabrueck, Germany
- Research Center for Cellular Nanoanalytics, Osnabrueck (CellNanOs), Osnabrueck University, 49076 Osnabrueck, Germany
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Second-Order Raman Scattering in Ferroelectric Ceramic Solid Solutions LiNbxTa1−xO3. CRYSTALS 2022. [DOI: 10.3390/cryst12040456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
In the second-order Raman spectra of ceramic solid solutions, LiNbxTa1−xO3 weak overtone bands of fully symmetric fundamental polar excitations were observed for the first time. The frequencies of the two bands exceeded the value of the overtone frequency corresponding to the fully symmetrical vibration 4A1(z). The possibility of the existence of phonon bound states of the antipolar type in the vibrational spectrum of LiNbxTa1−xO3 ceramics is predicted.
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Abstract
The recent Special Issue on lithium niobate (LiNbO3) is dedicated to Prof. Schirmer and his topics and contains nineteen papers, out of which seven review various aspects of intrinsic and extrinsic defects in single crystals, thin films, and powdered phases; six present brand-new results of basic research, including two papers on Li(Nb,Ta)O3 mixed crystals; and the remaining six are related to various optical and/or thin film applications.
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‘Horror Vacui’ in the Oxygen Sublattice of Lithium Niobate Made Affordable by Cationic Flexibility. CRYSTALS 2021. [DOI: 10.3390/cryst11070764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present review is intended for a broader audience interested in the resolution of the several decades-long controversy on the possible role of oxygen-vacancy defects in LiNbO3. Confronting ideas of a selected series of papers from classical experiments to brand new large-scale calculations, a unified interpretation of the defect generation and annealing mechanisms governing processes during thermo- and mechanochemical treatments and irradiations of various types is presented. The dominant role of as-grown and freshly generated Nb antisite defects as traps for small polarons and bipolarons is demonstrated, while mobile lithium vacancies, also acting as hole traps, are shown to provide flexible charge compensation needed for stability. The close relationship between LiNbO3 and the Li battery materials LiNb3O8 and Li3NbO4 is pointed out. The oxygen sublattice of the bulk plays a much more passive role, whereas oxygen loss and Li2O segregation take place in external or internal surface layers of a few nanometers.
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