Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464894
V. Gomozov, S. Deribo, G. Tulskiy, L. Skatkov
Changes in surface properties of anodic crystal films Nb2O5 during the extraction of oxygen anions from near-surface layer are considered. It is shown that the anion extraction brings about a phase transition in oxide which is accompanied by a change in conductivity resulting from structure distortion occurring during disordering in oxide crystals.
{"title":"On some peculiarities of surface properties of niobium anodic oxide crystals","authors":"V. Gomozov, S. Deribo, G. Tulskiy, L. Skatkov","doi":"10.1109/OMEE.2012.6464894","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464894","url":null,"abstract":"Changes in surface properties of anodic crystal films Nb2O5 during the extraction of oxygen anions from near-surface layer are considered. It is shown that the anion extraction brings about a phase transition in oxide which is accompanied by a change in conductivity resulting from structure distortion occurring during disordering in oxide crystals.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"21 1","pages":"126-126"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89598604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464791
A. V. Shevchenko, V. V. Tsukrenko, E. V. Dudnik, A. Ruban
X-ray diffraction, BET measurements, scanning electron and optical microscopy were used to analyze the properties variation of hydrothermal nanocrystalline powder with a composition 90 wt% Al2O3-10 wt%ZrO2 (CeO2, Y2O3) after thermal treatment in the temperature range 400–1300 °C. The composition of the ZrO2-based solid solution was (mol %) 90ZrO2-8CeO2-2Y2O3. It was found that α-Al2O3 is formed at 850 °C. Phase transformation F-ZrO2⇆T-ZrO2 occurred at 1000 °C. Produced powder was sintered at 1300 °C. The present investigation demonstrates that heat treatment of composite nanocrystalline powders gives rise to complex processes. Understanding of such processes makes it possible to optimize conditions for fabrication of advanced ceramics with tailored properties.
{"title":"Nanocrysrtalline Powders in the A12O3-ZrO2-CeO2-Y2O3 system for high-performance ceramics","authors":"A. V. Shevchenko, V. V. Tsukrenko, E. V. Dudnik, A. Ruban","doi":"10.1109/OMEE.2012.6464791","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464791","url":null,"abstract":"X-ray diffraction, BET measurements, scanning electron and optical microscopy were used to analyze the properties variation of hydrothermal nanocrystalline powder with a composition 90 wt% Al<inf>2</inf>O<inf>3</inf>-10 wt%ZrO<inf>2</inf> (CeO<inf>2</inf>, Y<inf>2</inf>O<inf>3</inf>) after thermal treatment in the temperature range 400–1300 °C. The composition of the ZrO<inf>2</inf>-based solid solution was (mol %) 90ZrO<inf>2</inf>-8CeO<inf>2</inf>-2Y<inf>2</inf>O<inf>3</inf>. It was found that α-Al<inf>2</inf>O<inf>3</inf> is formed at 850 °C. Phase transformation F-ZrO<inf>2</inf>⇆T-ZrO<inf>2</inf> occurred at 1000 °C. Produced powder was sintered at 1300 °C. The present investigation demonstrates that heat treatment of composite nanocrystalline powders gives rise to complex processes. Understanding of such processes makes it possible to optimize conditions for fabrication of advanced ceramics with tailored properties.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"1 1","pages":"79-80"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79717381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464799
O. Buryy, S. Ubizskii
The heat generation processes are considered for passively Q-switched YAG:Nd/YAG:Cr microchip laser. The distributions of the temperature, the refractive index and the deformations of laser crystal are determined. At the given profile of refractive index and deformations of the active element, the laser beam radius and the divergence are calculated.
{"title":"The heat generation processes in Q-switched YAG:Nd/YAG:Cr microchip laser and their influence on the parameters of laser radiation","authors":"O. Buryy, S. Ubizskii","doi":"10.1109/OMEE.2012.6464799","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464799","url":null,"abstract":"The heat generation processes are considered for passively Q-switched YAG:Nd/YAG:Cr microchip laser. The distributions of the temperature, the refractive index and the deformations of laser crystal are determined. At the given profile of refractive index and deformations of the active element, the laser beam radius and the divergence are calculated.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"34 5 1","pages":"177-178"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76418980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464794
A. T. Ince, M. Torun, M. Yukselici
CdTe nanocrystals embedded in matrixes such as, glass, plastic and, aqueous solution have been investigated extensively due to their potential applications in nonlinear optical devices, biotechnology and medicine. When the size of bulk semiconductor is reduced to nanometer scales, the crystal gains new optical and electronic properties. Energy levels are quantized as in atoms and the energy difference between levels widens with the inverse of the size squared. CdTe nanocrystals were grown in glass by solid-state phase precipitation at the above glass transition temperature. A size dependent blue shift in the asymptotic absorption edge was observed in optical absorption spectra. The crystalline composition was studied by Resonant Raman spectroscopy. The width of the optical absorption tail at long wavelengths depends on the spread of electron energy levels within the structure, called the Urbach energy, which was calculated depending on size. We observe that the Urbach tail narrows as the surface to volume ratio of the nanocrystals decreases.
{"title":"An urbach study of the degree of structural disorder in cdte nanocrystals in glass matrix","authors":"A. T. Ince, M. Torun, M. Yukselici","doi":"10.1109/OMEE.2012.6464794","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464794","url":null,"abstract":"CdTe nanocrystals embedded in matrixes such as, glass, plastic and, aqueous solution have been investigated extensively due to their potential applications in nonlinear optical devices, biotechnology and medicine. When the size of bulk semiconductor is reduced to nanometer scales, the crystal gains new optical and electronic properties. Energy levels are quantized as in atoms and the energy difference between levels widens with the inverse of the size squared. CdTe nanocrystals were grown in glass by solid-state phase precipitation at the above glass transition temperature. A size dependent blue shift in the asymptotic absorption edge was observed in optical absorption spectra. The crystalline composition was studied by Resonant Raman spectroscopy. The width of the optical absorption tail at long wavelengths depends on the spread of electron energy levels within the structure, called the Urbach energy, which was calculated depending on size. We observe that the Urbach tail narrows as the surface to volume ratio of the nanocrystals decreases.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"73 1 1","pages":"73-74"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77174273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464756
L. Kernazhitsky, V. Shymanovska, T. Gavrilko, V. V. Naumov, T. Khalyavka, V. Kshnyakin
Nanocrystalline titanium-manganese mixed oxides (TMMO) with Mn content of 13–16 at. % were first synthesized by manganese hydroxide precipitation on anatase or rutile particles. UV-vis absorption spectra were investigated in 2.4–6.0 eV region and revealed that compared with pure TiO2 the presence of manganese oxides results in an increase of the absorption intensity and significant red shift of the TMMO absorption edge. Photocatalytic activity of pure TiO2, Mn2+ doped TiO2 and TMMO during the photocatalytic decomposition of the safranine dye under UV irradiation was studied. A great improvement of photocatalytic activity is registered for Mn2+-doped TiO2 (anatase and rutile), and rutile-based TMMO sample.
{"title":"Influence of manganese oxides on the optical absorption and photocatalytic activities of titanium dioxide","authors":"L. Kernazhitsky, V. Shymanovska, T. Gavrilko, V. V. Naumov, T. Khalyavka, V. Kshnyakin","doi":"10.1109/OMEE.2012.6464756","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464756","url":null,"abstract":"Nanocrystalline titanium-manganese mixed oxides (TMMO) with Mn content of 13–16 at. % were first synthesized by manganese hydroxide precipitation on anatase or rutile particles. UV-vis absorption spectra were investigated in 2.4–6.0 eV region and revealed that compared with pure TiO<inf>2</inf> the presence of manganese oxides results in an increase of the absorption intensity and significant red shift of the TMMO absorption edge. Photocatalytic activity of pure TiO<inf>2</inf>, Mn<sup>2+</sup> doped TiO<inf>2</inf> and TMMO during the photocatalytic decomposition of the safranine dye under UV irradiation was studied. A great improvement of photocatalytic activity is registered for Mn<sup>2+</sup>-doped TiO<inf>2</inf> (anatase and rutile), and rutile-based TMMO sample.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"275 1","pages":"303-304"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86362327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464797
O. Krupych, V. Savaryn, I. Skab, R. Vlokh
A new technique is suggested for determination of piezooptic coefficients, which represents a combination of digital imaging laser interferometry and a canonical four-point bending method. The design of interferometer, measurement procedures, and data processing are described in detail. Potentials of the present technique are tested on the example of widely used optical borosilicate glass BK7. High enough precision, together with unambiguity in determination of the sign of both piezooptic (πqm) and photoelastic (pqm) coefficients, allow us to claim it to be one of the most accurate and reliable techniques for the measurements of pqm and pqm parameters.
{"title":"New method for piezooptic coefficients measurements based on four-point bending","authors":"O. Krupych, V. Savaryn, I. Skab, R. Vlokh","doi":"10.1109/OMEE.2012.6464797","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464797","url":null,"abstract":"A new technique is suggested for determination of piezooptic coefficients, which represents a combination of digital imaging laser interferometry and a canonical four-point bending method. The design of interferometer, measurement procedures, and data processing are described in detail. Potentials of the present technique are tested on the example of widely used optical borosilicate glass BK7. High enough precision, together with unambiguity in determination of the sign of both piezooptic (πqm) and photoelastic (pqm) coefficients, allow us to claim it to be one of the most accurate and reliable techniques for the measurements of pqm and pqm parameters.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"16 1","pages":"181-182"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84242675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464777
L. A. Tiphlova, A. S. Monayenkova, I. Romanova, V. Alyoshin
The solid solutions La2−xSrxCuO4−δ (0 ≤ x(Sr) ≤ 1.2) in La2CuO4 - Sr2CuO3 system were synthesized and characterized by x-ray diffraction and chemical analyses. The enthalpies of reaction La2−xSrxCuO4−δ with 1 N hydrochloric acid were measured in hermetic swinging isoperibolic calorimeter at 298.15 K. The Gibbs energies were assessed from thermochemical data. It was estimated that the solid solution is thermodynamically unstable at x(Sr) > 0.6.
{"title":"Thermodynamical assessment of stability La2−xSrxCuO4−δ solid solutions","authors":"L. A. Tiphlova, A. S. Monayenkova, I. Romanova, V. Alyoshin","doi":"10.1109/OMEE.2012.6464777","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464777","url":null,"abstract":"The solid solutions La<inf>2−x</inf>Sr<inf>x</inf>CuO<inf>4−δ</inf> (0 ≤ x(Sr) ≤ 1.2) in La<inf>2</inf>CuO<inf>4</inf> - Sr<inf>2</inf>CuO<inf>3</inf> system were synthesized and characterized by x-ray diffraction and chemical analyses. The enthalpies of reaction La<inf>2−x</inf>Sr<inf>x</inf>CuO<inf>4−δ</inf> with 1 N hydrochloric acid were measured in hermetic swinging isoperibolic calorimeter at 298.15 K. The Gibbs energies were assessed from thermochemical data. It was estimated that the solid solution is thermodynamically unstable at x(Sr) > 0.6.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"48 1","pages":"112-113"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85885868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464811
L. Arizmendi, E. Ambite, J. Plaza, F. Jaque
In this work some aspects of point defects produced in lithium niobate crystals by doping and thermal treatments are studied. The effect of oxidation and reduction processes on pure and doped samples is analyzed. In particular, results of visible and infrared optical absorption, photovoltaic behavior, paramagnetic resonance and holographic fixing parameters are considered to understand the photorefractive properties and optical damage inhibition in crystals co-doped with Fe and different concentrations of optical damage resistant impurities. The behavior of OH-centers and its role on photorefractive hologram fixing is also considered.
{"title":"Point defects physics in lithium niobate related to optical damage resistance, photorefractive holographic properties and applications","authors":"L. Arizmendi, E. Ambite, J. Plaza, F. Jaque","doi":"10.1109/OMEE.2012.6464811","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464811","url":null,"abstract":"In this work some aspects of point defects produced in lithium niobate crystals by doping and thermal treatments are studied. The effect of oxidation and reduction processes on pure and doped samples is analyzed. In particular, results of visible and infrared optical absorption, photovoltaic behavior, paramagnetic resonance and holographic fixing parameters are considered to understand the photorefractive properties and optical damage inhibition in crystals co-doped with Fe and different concentrations of optical damage resistant impurities. The behavior of OH-centers and its role on photorefractive hologram fixing is also considered.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"8 1","pages":"149-150"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86754153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464805
A. Aşıkoğlu, M. H. Yükselici, D. Bulut, D. Sugak, I. Solskii, I. Syvorotka, Y. Zhydachevskii, S. Ubizskii, O. Buryy
Pure and doped lithium niobate (LiNbO3) crystals heat treated at temperatures up to 1000°C under reduced/oxidized atmospheres were studied through normal incidence transmission ellipsometry in which a laser with a wavelength of 632.8 nm was employed. The differences in refractive indices between two orthogonal directions were calculated. Results show that the birefringence varies depending on thermal history of the samples.
{"title":"The effect of high temperature heat treatment on the directional homogeneity of LiNbO3 crystal studied through transmission ellipsometry","authors":"A. Aşıkoğlu, M. H. Yükselici, D. Bulut, D. Sugak, I. Solskii, I. Syvorotka, Y. Zhydachevskii, S. Ubizskii, O. Buryy","doi":"10.1109/OMEE.2012.6464805","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464805","url":null,"abstract":"Pure and doped lithium niobate (LiNbO3) crystals heat treated at temperatures up to 1000°C under reduced/oxidized atmospheres were studied through normal incidence transmission ellipsometry in which a laser with a wavelength of 632.8 nm was employed. The differences in refractive indices between two orthogonal directions were calculated. Results show that the birefringence varies depending on thermal history of the samples.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"57 1","pages":"161-162"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89161332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-09-01DOI: 10.1109/OMEE.2012.6464887
Y. Zakharko, A. Luchechko, I. Solskii
Emission spectra under UV and X-ray excitations, as well as luminescence decay kinetics of CaMoO4 single crystals and CaMoO4-CaWO4 mixed structures were studied. The broad luminescence bands with maxima at 425 and 530 nm correspond to CaWO4 and CaMoO4 crystals, respectively. The decay kinetics show non-single exponential behavior for all investigated CaMoO4-CaWO4 samples at room temperature.
{"title":"Oxygen-related defects and luminescence properties of CaMoO4 single crystals and CaMoO4-CaWO4 compounds","authors":"Y. Zakharko, A. Luchechko, I. Solskii","doi":"10.1109/OMEE.2012.6464887","DOIUrl":"https://doi.org/10.1109/OMEE.2012.6464887","url":null,"abstract":"Emission spectra under UV and X-ray excitations, as well as luminescence decay kinetics of CaMoO<inf>4</inf> single crystals and CaMoO<inf>4</inf>-CaWO<inf>4</inf> mixed structures were studied. The broad luminescence bands with maxima at 425 and 530 nm correspond to CaWO<inf>4</inf> and CaMoO<inf>4</inf> crystals, respectively. The decay kinetics show non-single exponential behavior for all investigated CaMoO<inf>4</inf>-CaWO<inf>4</inf> samples at room temperature.","PeriodicalId":6332,"journal":{"name":"2012 IEEE International Conference on Oxide Materials for Electronic Engineering (OMEE)","volume":"126 1","pages":"171-171"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77751022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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