Optical Materials: X最新文献

{"title":"Study of defect formation mechanisms in Li2ZrO3/MgLi2ZrO4 ceramics using EPR spectroscopy","authors":"Dmitriy I. Shlimas ,&nbsp;Ainagul A. Khametova ,&nbsp;Artem L. Kozlovskiy ,&nbsp;Maxim V. Zdorovets","doi":"10.1016/j.omx.2024.100396","DOIUrl":"10.1016/j.omx.2024.100396","url":null,"abstract":"<div><div>The article presents the results of experimental studies of the effect of the stabilizing MgO dopant using the electron spin resonance (ESP) method on enhancement of the stability of Li₂ZrO₃ ceramics to defect formation processes and accumulation of radiolysis products in the near-surface layer in the case of high-dose irradiation with protons simulating the hydrogenation effects characteristic of processes associated with tritium production. During the conducted studies, it was established that the addition of the stabilizing MgO dopant results in formation of inclusions in the form of the tetragonal MgLi₂ZrO₄ phase, which leads to an increase in the resistance of the near-surface layers to destructive damage due to the accumulation of structural damage (oxygen vacancies and point defects), as well as products of the physicochemical processes of radiolysis, characteristic of high irradiation fluence values. It was found that in the case of unmodified Li₂ZrO₃ ceramics, the formation of HC₂ – centers is observed at a fluence of 10¹⁶ proton/cm², while for two-phase ceramics, the formation of HC₂ – centers is observed at higher fluences, while the intensity of the bands is significantly less than in the case of single-phase unmodified ceramics. The difference in the nature of changes in the intensities of singlet bands responsible for the presence of vacancy defects in the damaged layer, as well as HC₂ – centers for single-phase and two-phase ceramics is a direct confirmation of the inhibition of structural degradation mechanisms in two-phase ceramics.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100396"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of the conduction band of BaCl2 on the thermal quenching of the Tm2+ 4f125d1→4f13 and 4f13→4f13 luminescence in orthorhombic BaCl2:Tm2+/3+","authors":"M.P. Plokker,&nbsp;H.T. Hintzen","doi":"10.1016/j.omx.2024.100389","DOIUrl":"10.1016/j.omx.2024.100389","url":null,"abstract":"<div><div>The positioning of the Tm²⁺ 4f¹²5d¹ and 4f¹³ energy levels as relative to the conduction band of the orthorhombic BaCl₂ host lattice has been determined. Therefore, the energies of the Tm²⁺ 4f¹²5d¹-and excited 4f¹³-level were retrieved, as relative to the Tm²⁺ 4f¹³ ground state. In addition, the energy for exciton creation in the orthorhombic BaCl₂ host lattice was established, from which the bandgap energy was determined. This value was found to correspond quite well to known literature values. Furthermore, the Tm³⁺-Cl^- charge transfer transition was determined, from which the energy difference between the Tm²⁺ 4f¹³ ground state and the top of the BaCl₂ valence band was deduced. A host referred binding energy scheme deduced for BaCl₂:Tm²⁺ then showed that the lowest energy Tm²⁺ 4f¹²5d¹-levels are positioned 0.3–0.5 eV below the BaCl₂ conduction band. Room temperature photo-excitation into this level will then most likely result in thermal ionization effects that have an impact on the Tm²⁺ 4f¹²5d¹→4f¹³ and 4f¹³→4f¹³ luminescence and corresponding quantum yield.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100389"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143181703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preface to the special issue after ESTE 2023 conference","authors":"Dariusz Hreniak ,&nbsp;Mariusz Stefański ,&nbsp;Wiesław Stręk ,&nbsp;Rober Tomala ,&nbsp;Eugeniusz Zych","doi":"10.1016/j.omx.2024.100379","DOIUrl":"10.1016/j.omx.2024.100379","url":null,"abstract":"","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100379"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence of copper-doped α-quartz crystal after oxygen treatment","authors":"A. Trukhin","doi":"10.1016/j.omx.2024.100381","DOIUrl":"10.1016/j.omx.2024.100381","url":null,"abstract":"<div><div>Treatment of copper-doped natural α-quartz in oxygen atmosphere at 1200 °C leads to changes in luminescence properties. The luminescence center of AlO₄⁻-Cu⁺ is modified. The intensity is low in the annealed sample and increases after X-ray irradiation at 293 K. Annealing of the irradiated sample leads to a strong peak of thermally stimulated luminescence (TSL) at ∼500 K. Its spectral composition is mainly due to the AlO₄⁻-Cu⁺ center. Irradiation of the sample treated with oxygen at 77 K gives a new TSL peak at ∼180 K and a peak at 244 K existing in the untreated sample. Both peaks were attributed to Cu^o centers released from different sites and recombined with a hole in AlO₄ having additional oxygen. The introduction of copper ions into quartz removes alkali metal ions and eliminates the corresponding luminescence, but after treatment in oxygen, luminescence with similar parameters is restored at low temperatures. In this case, only the glow of the AlO₄⁻-Cu⁺ center is observed in the recombination luminescence (TSL and afterglow). Therefore, modification of the AlO₄⁻-Cu ⁺ center with oxygen imparts to this center properties similar to the complex center AlO₄⁻ (K, Na or Li ion) with monovalent aluminum ions, although the alkali ions are replaced by copper ions. The oxygen-treated sample exhibits an increased efficiency of energy transfer by excitons to the luminescence center, measured as excitation spectra in the region of fundamental absorption of silicon dioxide. The X-ray excitation of the self-trapped exciton luminescence does not depend on oxygen treatment. Also, the spectra of intrinsic optical reflection and Raman scattering do not change compared to the untreated sample. The obtained result is interpreted as a modification of the defect by high-temperature treatment in oxygen.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100381"},"PeriodicalIF":0.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of temperature factor during heavy ion irradiation on structural disordering of SiC ceramics","authors":"Kymbat M. Tynyshbayeva ,&nbsp;Artem L. Kozlovskiy","doi":"10.1016/j.omx.2024.100383","DOIUrl":"10.1016/j.omx.2024.100383","url":null,"abstract":"<div><div>The paper presents the results of the influence of heavy ion irradiation on the formation of anisotropic distortions of the crystal structure and electron density distribution in SiC ceramics. The assessment of the change in the properties of the damaged layer was carried out using Raman spectroscopy methods, and using data on structural changes obtained using the X-ray diffraction method. The observed alterations in the spectral modes E₁(TO), E₂(TO) and A₁(LO) depending on the irradiation temperature indicate an anisotropic distortion of the structure, which has a clearly expressed dependence on the irradiation temperature, as well as the type of ions used for irradiation. The assessment results of changes in the electron density distribution contingent upon the irradiation temperature for both types of ion irradiation showed a direct correlation between the irradiation temperature growth and the electron density anisotropic distortion caused by the deformation of chemical bonds. In turn, the combination of the effects of thermal heating and ionization processes causes deformation distortion of chemical bonds, which is most pronounced at high irradiation temperatures, for which thermal expansion of the crystal lattice and accelerated diffusion of vacancy defects play a key role in disordering.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100383"},"PeriodicalIF":0.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and optical properties of LaSrGaO4:RE3+ (RE = Sm, Eu, Ho) single crystals via optical float zone method","authors":"Hasan Yilmaz ,&nbsp;Masahiko Isobe ,&nbsp;Oliver Clemens ,&nbsp;Markus Suta ,&nbsp;Pascal Puphal","doi":"10.1016/j.omx.2024.100380","DOIUrl":"10.1016/j.omx.2024.100380","url":null,"abstract":"<div><div>The advancement of synthesis of materials with luminescence properties of lanthanoid ions in various single crystalline host compounds with low phonon energies has facilitated the optimization of numerous materials to meet the specific optical properties required for diverse applications such as new energy resource exploration, light-emitting diodes (LEDs), quantum dot displays, laser technology, sensors, telecommunications, medical diagnostics and more. Enhanced analyses of the luminescence mechanism of lanthanoid ions in various host compounds, which have captivated researchers for many years and culminated in the development of innovative materials for optical applications. To obtain a deeper understanding of the luminescence mechanism of Sm³⁺, Eu³⁺, and Ho³⁺ ions incorporated into the Ruddlesden-Popper-type host compounds (La_1-<em>x</em><em>RE</em>_<em>x</em>)SrGaO₄ (<em>RE</em> = Sm, Eu, Ho and <em>x</em> = 0; 0.05; 0.10) high quality single crystals with homogenous activator distribution grown by the optical floating zone (OFZ) method were examined systematically. X-ray diffraction (XRD) characterization shows that the compound crystallizes in a tetragonal crystal system with the space group <em>I</em>4/<em>mmm</em> (no. 139) with homogenous distribution of the dopants shown via backscattered electron (BSE) imaging. Photoluminescence studies at both 77 K and 298 K reveal that the incorporated lanthanoid ions brightly emit and even show unusual transitions due to the low cutoff phonon energy of the host compound that limits non-radiative loss pathways. Together with a high physical density of ∼6.4 g/cm³, these phosphors could be conceptualized as interesting candidates for X-ray imaging phosphors aiming at high light yields.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"25 ","pages":"Article 100380"},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical and EPR study of Mn4+ ions in different crystal environments in Mn, Li co-doped MgO","authors":"L. Borkovska ,&nbsp;K. Kozoriz ,&nbsp;I. Vorona ,&nbsp;O. Gudymenko ,&nbsp;S. Ponomaryov ,&nbsp;O. Melnichuk ,&nbsp;V. Trachevskii ,&nbsp;O. Chukova ,&nbsp;L. Khomenkova","doi":"10.1016/j.omx.2024.100378","DOIUrl":"10.1016/j.omx.2024.100378","url":null,"abstract":"<div><div>The influence of Li ion on the symmetry of Mn⁴⁺ center and its photoluminescence (PL) in MgO:0,01%Mn, 3 % Li ceramics is studied by the X-ray diffraction, electron paramagnetic resonance (EPR), PL and optical absorption methods. It is shown that Li co-doping stimulates conversion of Mn²⁺ on Mg site into Mn⁴⁺ and can decrease symmetry of Mn⁴⁺ in a case of their specific close arrangement in the crystal lattice. Two kinds of Mn⁴⁺ centers are identified in the EPR and PL spectra: cubic Mn⁴⁺ and tetragonal complex Mn⁴⁺-Li⁺. The parameters of corresponding EPR centers are estimated from the experimental spectra (g_cub = 1.994, |A|_cub = 70.9 × 10⁴ cm⁻¹; g_1tetr = g_2tetr = 1.994, g_3tetr = 1.993, |A|_tetr = 71 × 10⁴ cm⁻¹, |D|_tetr = 220 × 10⁴ cm⁻¹). The PL lines observed in the low temperature PL spectra are assigned to the specific Mn⁴⁺ related centers using a complementary study of PL excitation spectra and temperature dependent PL spectra. The lines at 654 nm and 671 nm are ascribed to R-line of Mn⁴⁺ in a site of cubic symmetry and its phonon overtone, correspondingly, as well as the lines at 666 nm and 681 nm are attributed to R2 line of Mn⁴⁺ in site with tetragonal symmetry and to its phonon overtone, correspondingly. It is shown that in Mn doped MgO ceramics made without intentional Li co-doping, the cubic Mn⁴⁺ center can be present and contribute to the PL spectra.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100378"},"PeriodicalIF":0.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of spectroscopic properties in the YXO4 compounds (where X = V5+, P5+, As5+) doped with Eu3+ ions","authors":"Adam Watras ,&nbsp;Marta Kardach ,&nbsp;Katarzyna Szyszka ,&nbsp;Paulina Sobierajska ,&nbsp;Aleksandra Bartkowiak ,&nbsp;Rafal J. Wiglusz","doi":"10.1016/j.omx.2024.100377","DOIUrl":"10.1016/j.omx.2024.100377","url":null,"abstract":"<div><div>In the present work, a co-precipitation method was employed to prepare nanosized YXO₄ (X = V⁵⁺, P⁵⁺, As⁵⁺) doped with Eu³⁺ ions. The raw nanomaterials have been thermally treated in temperature range between 300 and 1100 °C for 3h. The XRD analysis demonstrated that the powders were single-phase with high crystallite dispersion. The studies focused on investigating the systematic relationship between crystallographic parameters and spectroscopic properties. The average size of the obtained materials was 30 nm for YVO4, 35 nm for YPO₄, and 20 nm for YAsO₄, respectively.</div><div>Moreover, the emission and excitation spectra, although typical for Eu³⁺ ions, demonstrated some degree of variability with calcination temperatures and doping concentration. Thermal luminescence quenching was typical for YPO₄ and YAsO₄ samples, while for the YVO₄ samples, the intensity of emission increased, reaching its maximum at 725 K. To explain this phenomenon, excitation spectra in function of temperature were measured.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100377"},"PeriodicalIF":0.0,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of residual mechanical stresses and vacancy defects on the diffusion expansion of the damaged layer during irradiation of BeO ceramics","authors":"Azamat E. Ryskulov ,&nbsp;Igor A. Ivanov ,&nbsp;Artem L. Kozlovskiy ,&nbsp;Marina Konuhova","doi":"10.1016/j.omx.2024.100375","DOIUrl":"10.1016/j.omx.2024.100375","url":null,"abstract":"<div><div>The paper presents the results of a study on the application of Raman and UV spectroscopy methods to determine the structural damage kinetics in the near-surface layer of BeO ceramics caused by high-dose irradiation with He²⁺ ions. Interest in this type of ceramics is due to the combination of its structural and thermophysical parameters, making these ceramics one of the promising classes of materials for microelectronics and structural materials for nuclear reactors, with the possibility of operation in conditions of heightened radiation background. According to the conducted studies, it was established that with the irradiation fluence growth, changes in the nature of deformation structural distortions associated with the accumulation of residual mechanical stresses of tensile and compressive types are observed. At irradiation fluences of 10¹⁶–5 × 10¹⁶ Не²⁺/cm², tensile stresses play a dominant role in structural distortions, while the value of compressive stresses at fluence growth makes up a small share in the overall nature of the deformations. Moreover, an elevation in the irradiation fluence above 5 × 10¹⁶ He²⁺/cm² leads to a rise in the concentration of defects caused by the formation of oxygen vacancies, as well as He-V_O type complexes, the presence of which is indicated by the halo intensity growth in the Raman spectra, as well as a change in the intensity of the absorption bands. Analysis of changes in thermophysical parameters revealed that a rise in structural distortions associated with the accumulation of complex defects results in thermal conductivity reduction and a deterioration in heat transfer processes associated with partial amorphization of the damaged layer. Moreover, the established direct relationship between the value of residual mechanical stresses and the degradation of thermal conductivity indicates the cumulative effect of destructive changes caused by irradiation, as well as the influence of diffusion mechanisms on the damaged layer thickness growth.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100375"},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of irradiation temperature on the mobility of structural and vacancy defects in the damaged layer of Li2ZrO3 ceramics","authors":"Bauyrzhan K. Abyshev ,&nbsp;Sholpan G. Giniyatova ,&nbsp;Artem L. Kozlovskiy","doi":"10.1016/j.omx.2024.100376","DOIUrl":"10.1016/j.omx.2024.100376","url":null,"abstract":"<div><div>The paper presents the assessment results of the irradiation temperature effect on the change in the type of structural defects caused by irradiation with helium ions in the near-surface layer of Li₂ZrO₃ ceramics, as well as determining the nature of structural damage using the electron paramagnetic resonance method in the case of irradiation fluence variation. During characterization of the structural changes caused by helium ion irradiation, the main attention was paid to detailing the type of structural defects and radiolysis products arising during irradiation, alongside alterations in their concentration using the electron paramagnetic resonance method. During the experiments, it was determined that the observed effects of thermally stimulated mobility of vacancy defects in the damaged layer caused by irradiation with helium ions indicate a positive effect of thermal heating of samples during irradiation at low fluences. This effect consists in a decline in the number of oxygen vacancies in the damaged layer at low irradiation fluences (10¹⁵–10¹⁶ cm⁻²), the concentration of which was determined using the EPR method, and the observed structural changes at low irradiation fluences in the case of an elevation in irradiation temperatures are associated with deformation distortion of the crystalline structure of ceramics caused by transformation energy processes, and thermal expansion effects.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100376"},"PeriodicalIF":0.0,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}