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LiNbO3 Single Crystal (linbo3 + single_crystal)
Selected AbstractsGrowth and characterization of near stoichiometric LiNbO3 single crystalCRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2007S. H. Yao Abstract A near stoichiometric LiNbO3 single crystal has been grown by the Czochralski method from a 58.5% Li melt hold in a large platinum crucible. High resolution X-ray rocking curves of 300 and 0006 reflections indicated that the near stoichiometric LiNbO3 crystal possesses the high structural quality. Compared with the congruent LiNbO3, the near stoichiometric LiNbO3 possesses shorter ultraviolet absorption edge, thus higher Li concentration. The OH, infrared absorption band analyses showed that the Li concentration in the near stoichiometric LiNbO3 crystal is higher than that in the congruent LiNbO3 crystal. This result is in good agreement with that of the ultraviolet absorption edge. The electro-optic (EO) coefficient ,22 of the near stoichiometric LiNbO3 crystal was measured to be 6.75 pm/V higher than that of congruent LiNbO3 crystal. It also proves the near stoichiometric LiNbO3 electro-optic Q-switched requires a low driving voltage and it is advantageous for the device performance. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Inhomogeneity of composition in near-stoichiometric LiNbO3 single crystal grown from Li rich meltCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2006L. Gao Abstract A near-stoichiometric LiNbO3 single crystal has been grown by the Czochralski technique from a melt of 58.5 mol% Li2O. Its composition homogeneity was assessed by measuring the UV absorption edge. It was found that the maximum composition difference is about 0.03 mol% in the radial direction and 0.05 mol% in the axial direction. Differential scanning calorimetry (DSC) analysis was performed on the powder from the synthesized raw material and the frozen melt after crystal growth. The analytical results indicate that, during crystal growth, the magnitude of lithium volatilization from the melt surface is more than the degree of segregation from the crystal. The volatilized lithium diffuses into the crystal to compensate for the lithium segregation in the LiNbO3 crystal. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fine surface processing of LiNbO3 single crystals by maskless etching using NF3 system gas plasma RIEELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 2 2010Teruaki Omata Abstract The possibility of deep etching by plasma reactive ion etching (RIE) without an etching-mask (maskless) for ,Z and +Z parts formed on the same surface of a partially polarization reversed LiNbO3 single crystal polarized in the direction of the c -axis is investigated. A NF3/H2 gas mixture was used. The etching rates and depths and the profiles of the etched surfaces were evaluated by atomic force microscopy (AFM) and optical microscopy. The etching rate for the ,Z surface was larger than that for the +Z surface. Extension of the +Z domain by partial polarization reversal was observed. Applying the high voltage quickly for partial polarization reversal, the area of the +Z domain was extended compared with the result obtained by applying the voltage slowly. An apparent step at the boundary between ,Z and +Z parts formed on the same surface was observed. Using a NF3/H2 gas mixture, the segments were removed efficiently. It is concluded that RIE etching using a NF3/H2 gas mixture is suitable for processing of LiNbO3 crystal surfaces without an etching mask, in contrast with a CF4/H2 gas mixture. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(2): 39,49, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10168 [source] Improvement in crystalline perfection, piezo-electric property and optical transparency of in-situ poled Fe,LiNbO3 single crystals by post growth annealing and polingPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2005G. C. Budakoti Abstract Crystalline perfection, piezoelectric response and optical transparency of in-situ poled Fe,LiNbO3 single crystals was studied. Very low angle grain boundaries and the variations in the piezoelectric charge constant d33 were observed in the as-grown crystals. Grain boundaries were successfully removed at higher annealing temperatures but the d33 value was decreased. Low crystalline perfection and d33 were observed after poling the annealed specimen. These parameters were improved by low temperature annealing followed by very slow cooling. FTIR spectra revealed that OH, and CO32, ionic defects were present in the as-grown crystals. The OH, ion concentration was reduced, CO32, ions were removed and optical quality was improved after annealing at higher temperatures. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Ion irradiation and reduction effect on the conductivity and optical absorption of heavily MgO-doped LiNbO3 single crystalsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2005V.F. Pichugin Abstract The confirmation of MgNb defects in heavily MgO doped LiNbO3 single crystals were investigated through optical absorption, electrical conductivity measurements, optical spectroscopy with nanosecond time resolution, and Raman spectroscopy technique. An increase in the MgO concentration up to 10 mole% provides an essential change of the luminescence of LiNbO3, the appearance of a supplementary optical absorption band at the 1.1 eV, an alteration of the Raman spectra caused by the formation of (MgNb) defects, a shift of the edge of the supplementary optical absorption due to ion irradiation toward the shorter wavelength region as the MgO concentration increases. The effect of Ar+ ions irradiation on the conduction of the MgO doped LiNbO3 samples was studied. The important role of reduction in modification of the conducting properties of the ion-irradiated crystals was established. The increase of the MgO concentration leads to a decrease of the reduction efficiency. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||