Pub Date : 2024-10-05DOI: 10.1016/j.omx.2024.100371
Amir Ashjari , Brian Topper , Lars H. Hess , Lucas Greiner , Jared Tolliver , Fiona Cormack , Dimitrios Palles , Efstratios I. Kamitsos , Mikhail G. Brik , Doris Möncke
Unusually high oxidation states of manganese were stabilized within a cesium-barium silicate (CBS) glass system of extremely high optical basicity. The highest basicity was obtained for the metasilicate glass 40Cs2O–10BaO–50SiO2 (mol%) with an optical basicity of = 0.81. The presence of Mn5+ (d2) as well as Mn6+ (d1) is confirmed by UV–Vis, photoluminescence, and Raman spectroscopy. The UV–Vis spectrum is dominated by the Mn3+ (d4) absorption at 526 nm for low-basicity glasses, which is replaced by a peak at 679 nm (Mn5+) and, finally, a band at 603 nm (Mn6+) in the glass with the highest basicity ( = 0.81). In this glass, the Mn5+/Mn6+ ratio varies with the melting conditions. Photoluminescence (PL) spectroscopy under 633 nm excitation confirms the presence of Mn5+, showing the narrow, forbidden 1E 3A2 transition located at 1191 nm with vibrational sidebands at 1245 nm and 1290 nm. The measured static fluorescence intensity due to Mn5+ grows exponentially with increasing optical basicity. The near infrared fluorescence decay was bi-exponential, with time constants of 14 and 51 μs. The absence of Mn4+ in CBS glasses was confirmed by PL and electron paramagnetic resonance (EPR) spectroscopy. Despite initial doping as MnO2, metastable Mn4+ disproportionates into lower and higher valent manganese species, followed by reduction or oxidation of manganese to a stable species as ruled by the basicity of the glass and oxygen availability during melting. A structural study of the glasses by Raman spectroscopy revealed a resonance enhancement effect for the symmetric stretching mode of MnO4-tetrahedra at ∼800 cm−1 with overtones observed at higher frequencies.
{"title":"Unusually high oxidation states of manganese in high optical basicity silicate glasses","authors":"Amir Ashjari , Brian Topper , Lars H. Hess , Lucas Greiner , Jared Tolliver , Fiona Cormack , Dimitrios Palles , Efstratios I. Kamitsos , Mikhail G. Brik , Doris Möncke","doi":"10.1016/j.omx.2024.100371","DOIUrl":"10.1016/j.omx.2024.100371","url":null,"abstract":"<div><div>Unusually high oxidation states of manganese were stabilized within a cesium-barium silicate (CBS) glass system of extremely high optical basicity. The highest basicity was obtained for the metasilicate glass 40Cs<sub>2</sub>O–10BaO–50SiO<sub>2</sub> (mol%) with an optical basicity of <span><math><mrow><mi>Λ</mi></mrow></math></span> = 0.81. The presence of Mn<sup>5+</sup> (d<sup>2</sup>) as well as Mn<sup>6+</sup> (d<sup>1</sup>) is confirmed by UV–Vis, photoluminescence, and Raman spectroscopy. The UV–Vis spectrum is dominated by the Mn<sup>3+</sup> (d<sup>4</sup>) absorption at 526 nm for low-basicity glasses, which is replaced by a peak at 679 nm (Mn<sup>5+</sup>) and, finally, a band at 603 nm (Mn<sup>6+</sup>) in the glass with the highest basicity (<span><math><mrow><mi>Λ</mi></mrow></math></span> = 0.81). In this glass, the Mn<sup>5+</sup>/Mn<sup>6+</sup> ratio varies with the melting conditions. Photoluminescence (PL) spectroscopy under 633 nm excitation confirms the presence of Mn<sup>5+</sup>, showing the narrow, forbidden <sup>1</sup>E <span><math><mrow><mo>→</mo></mrow></math></span><sup>3</sup>A<sub>2</sub> transition located at 1191 nm with vibrational sidebands at 1245 nm and 1290 nm. The measured static fluorescence intensity due to Mn<sup>5+</sup> grows exponentially with increasing optical basicity. The near infrared fluorescence decay was bi-exponential, with time constants of 14 and 51 μs. The absence of Mn<sup>4+</sup> in CBS glasses was confirmed by PL and electron paramagnetic resonance (EPR) spectroscopy. Despite initial doping as MnO<sub>2</sub>, metastable Mn<sup>4+</sup> disproportionates into lower and higher valent manganese species, followed by reduction or oxidation of manganese to a stable species as ruled by the basicity of the glass and oxygen availability during melting. A structural study of the glasses by Raman spectroscopy revealed a resonance enhancement effect for the symmetric stretching mode of MnO<sub>4</sub>-tetrahedra at ∼800 cm<sup>−1</sup> with overtones observed at higher frequencies.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100371"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419455","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}
Pub Date : 2024-10-05DOI: 10.1016/j.omx.2024.100370
Trinh Duc Thien , Nguyen Van Thang , Le T.M. Cham , Nguyen Dinh Lam
The co-precipitation technique was used to produce Zn1-x-yYbxAgyO nanomaterials. The Zn1-x-yYbxAgyO nanomaterials have higher photocatalytic activity compared to ZnO, owing to their exceptional optical and electrical characteristics. The results demonstrate that the Zn0.096Yb0.02Ag0.02O nanoparticles are capable of decomposing 98.2 % of RhB dye after 15 min by photodegradation. Moreover, studies have shown that superoxide radicals actively participate in the process of photodegradation.
{"title":"ZnYbAgO nanoparticles for the photocatalytic degradation","authors":"Trinh Duc Thien , Nguyen Van Thang , Le T.M. Cham , Nguyen Dinh Lam","doi":"10.1016/j.omx.2024.100370","DOIUrl":"10.1016/j.omx.2024.100370","url":null,"abstract":"<div><div>The co-precipitation technique was used to produce Zn<sub>1-x-y</sub>Yb<sub>x</sub>Ag<sub>y</sub>O nanomaterials. The Zn<sub>1-x-y</sub>Yb<sub>x</sub>Ag<sub>y</sub>O nanomaterials have higher photocatalytic activity compared to ZnO, owing to their exceptional optical and electrical characteristics. The results demonstrate that the Zn<sub>0.096</sub>Yb<sub>0.02</sub>Ag<sub>0.02</sub>O nanoparticles are capable of decomposing 98.2 % of RhB dye after 15 min by photodegradation. Moreover, studies have shown that superoxide radicals actively participate in the process of photodegradation.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100370"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419611","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}
Pub Date : 2024-10-05DOI: 10.1016/j.omx.2024.100369
Adil Z. Tuleushev , Fiona E. Harrison , Artem L. Kozlovskiy , Maxim V. Zdorovets
We present a new hypothesis and supporting experimental evidence about the essential role played by small impurities of dicarboxystilbene in the process of UV treatment of PET films irradiated with swift heavy ions (SHI). This treatment both forms highly selective membranes with permeability values comparable to natural ones (the track-UV technique) and sharply accelerates the etching of latent tracks in membrane production (the track-etching technique). We hypothesize (1) that these high permeability value is due to the presence of a molecular motor of an Archimedes screw type in the central part of the latent track formed by photoinduced trans-cis isomerization of dicarboxystilbene molecules that are anchored in helical conformations in the latent track; and (2) that the acceleration of etching rates is due to the preferential accumulation of phenanthrene-type molecules in the central part of the latent track due to the existence of a cyclization channel for photoexcited molecules of cis-dicarboxystilbene. In the presence of alkali solution, phenanthrene molecules release electrons which behave as strong anions in aqueous solution, catalyzing alkaline hydrolysis of PET molecules in the central part of the track. We present experimental observations of photoinduced changes in transmission light intensity after track-UV light treatment of both pristine and SHI irradiated PET films that confirm the presence of trans-cis isomerization of dicarboxystilbene molecules and show their contribution to the formation of new helical conformations in SHI irradiated PET films during the light treatment.
我们提出了一个新的假设，并通过实验证明了二羧基二苯乙烯的小杂质在用快速重离子（SHI）辐照 PET 薄膜的紫外线处理过程中所起的重要作用。这种处理方法既能形成高选择性膜，其渗透值可与天然膜媲美（轨迹-紫外线技术），又能在膜生产过程中大大加快潜在轨迹的蚀刻（轨迹-蚀刻技术）。我们的假设是：(1) 这些高渗透率值是由于在潜轨的中央部分存在阿基米德螺钉型分子马达，该分子马达是由潜轨中以螺旋构象固定的二羧基二苯乙烯分子经光诱导反式-顺式异构化形成的；(2) 加速蚀刻速率的原因是，由于存在顺式二羧基二苯乙烯光激发分子的环化通道，菲类分子优先聚集在潜迹的中央部分。在碱溶液中，菲分子释放出电子，这些电子在水溶液中表现为强阴离子，催化了潜迹中心部分 PET 分子的碱性水解。我们展示了原始 PET 薄膜和经 SHI 照射的 PET 薄膜在经过轨道-紫外光处理后透射光强度光诱导变化的实验观察结果，这些观察结果证实了二羧基二苯乙烯分子存在反式-顺式异构化，并显示了它们在光处理期间对经 SHI 照射的 PET 薄膜中新螺旋构象的形成所起的作用。
{"title":"Impact of dicarboxystilbene impurities on the properties of swift heavy ion latent tracks in PET films","authors":"Adil Z. Tuleushev , Fiona E. Harrison , Artem L. Kozlovskiy , Maxim V. Zdorovets","doi":"10.1016/j.omx.2024.100369","DOIUrl":"10.1016/j.omx.2024.100369","url":null,"abstract":"<div><div>We present a new hypothesis and supporting experimental evidence about the essential role played by small impurities of dicarboxystilbene in the process of UV treatment of PET films irradiated with swift heavy ions (SHI). This treatment both forms highly selective membranes with permeability values comparable to natural ones (the track-UV technique) and sharply accelerates the etching of latent tracks in membrane production (the track-etching technique). We hypothesize (1) that these high permeability value is due to the presence of a molecular motor of an Archimedes screw type in the central part of the latent track formed by photoinduced <em>trans-cis</em> isomerization of dicarboxystilbene molecules that are anchored in helical conformations in the latent track; and (2) that the acceleration of etching rates is due to the preferential accumulation of phenanthrene-type molecules in the central part of the latent track due to the existence of a cyclization channel for photoexcited molecules of <em>cis</em>-dicarboxystilbene. In the presence of alkali solution, phenanthrene molecules release electrons which behave as strong anions in aqueous solution, catalyzing alkaline hydrolysis of PET molecules in the central part of the track. We present experimental observations of photoinduced changes in transmission light intensity after track-UV light treatment of both pristine and SHI irradiated PET films that confirm the presence of <em>trans-cis</em> isomerization of dicarboxystilbene molecules and show their contribution to the formation of new helical conformations in SHI irradiated PET films during the light treatment.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100369"},"PeriodicalIF":0.0,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419456","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}
Expansion of the possibilities of using photoactive thin films with a unique combination of optical and morphological characteristics as a basis for creation of highly efficient catalysts for the aqueous media purification is one of the promising research areas in modern materials science, which has both fundamental significance and potential for practical application. This study examines the prospects for using modified thin CdSe films by substituting nickel or cobalt for cadmium and selenium as a basis for creating highly efficient catalysts for the aqueous media purification from heavy metals such as arsenic, manganese and iron. A rather inexpensive electrochemical synthesis method was proposed as a method for obtaining thin films, in which the substitution effect is achieved by addition of nickel or cobalt sulfates to the electrolyte, which allows obtaining films with an equally probable distribution of elements in the composition of the synthesized films. Optical spectroscopy methods were used as methods for characterization of the initial samples, which made it possible to establish the dependences of the change in the band gap and absorption bands on the composition of the synthesized films, as well as to anticipate the influence of morphological features on optical absorption. During the conducted studies it was established that partial substitution of nickel and cobalt for cadmium and selenium in the composition of films results in growth in the adsorption efficiency of heavy metals, alongside operation stability maintenance of modified films during cyclic tests. At the same time, enhancement of the adsorption efficiency of heavy metals for modified films is due to both an alteration in the optical properties of the films and morphological features associated with the specific surface area growth due to a reduction in the grain size and a more developed surface.
{"title":"Study of the applicability of ACdSe (A – Co, Ni) thin films as catalysts for heavy metal capture","authors":"Aliya Zh Omarova , Artem L. Kozlovskiy , Gulnaz Zh Moldabayeva","doi":"10.1016/j.omx.2024.100366","DOIUrl":"10.1016/j.omx.2024.100366","url":null,"abstract":"<div><div>Expansion of the possibilities of using photoactive thin films with a unique combination of optical and morphological characteristics as a basis for creation of highly efficient catalysts for the aqueous media purification is one of the promising research areas in modern materials science, which has both fundamental significance and potential for practical application. This study examines the prospects for using modified thin CdSe films by substituting nickel or cobalt for cadmium and selenium as a basis for creating highly efficient catalysts for the aqueous media purification from heavy metals such as arsenic, manganese and iron. A rather inexpensive electrochemical synthesis method was proposed as a method for obtaining thin films, in which the substitution effect is achieved by addition of nickel or cobalt sulfates to the electrolyte, which allows obtaining films with an equally probable distribution of elements in the composition of the synthesized films. Optical spectroscopy methods were used as methods for characterization of the initial samples, which made it possible to establish the dependences of the change in the band gap and absorption bands on the composition of the synthesized films, as well as to anticipate the influence of morphological features on optical absorption. During the conducted studies it was established that partial substitution of nickel and cobalt for cadmium and selenium in the composition of films results in growth in the adsorption efficiency of heavy metals, alongside operation stability maintenance of modified films during cyclic tests. At the same time, enhancement of the adsorption efficiency of heavy metals for modified films is due to both an alteration in the optical properties of the films and morphological features associated with the specific surface area growth due to a reduction in the grain size and a more developed surface.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100366"},"PeriodicalIF":0.0,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356639","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}
Pub Date : 2024-09-27DOI: 10.1016/j.omx.2024.100362
Nguyen Duy Thien , Tu Nguyen Ngoc , Sai Cong Doanh , Vuong Van Hiep , Le Quang Thao , Luu Manh Quynh , Le Viet Cuong , Nguyen Huy Tiep , Duc Thang Pham , Hoang Nam Nhat , Ngoc Dinh Nguyen
SiO2 opal crystals decorated with silver nanoparticles (AgNPs) have been successfully fabricated. SEM analysis revealed that the SiO2 opals have an ordered region of 25–30 μm2, and AgNPs are located into the gaps between the SiO2 nanospheres. The effect of the plasmons of AgNPs on the photoluminescence of SiO2 opal crystals were investigated. Under excitation of a 325 nm laser, we observed the quenching of the intrinsic defect emission in SiO2 as the concentration of AgNPs increased. The cause of the observed photoluminescence behavior is attributed to the interaction between surface plasmon induced by AgNPs and photoluminescence centers in SiO2 opal crystals. Then, we utilized SiO2 opals crystals decorated with AgNPs as a SERS substrate. The final enhancement factor of the Raman shift was 1.64 × 107, enabling the trace detection limit for a case of malachite green to be as low as 0.05 ppm, with a relative standard deviation of less than 1.75 %. This outcome suggests the potential for direct application of the prepared substrates in ultra-fast chemical analysis.
{"title":"Optical properties of SiO2 opal crystals decorated with silver nanoparticles","authors":"Nguyen Duy Thien , Tu Nguyen Ngoc , Sai Cong Doanh , Vuong Van Hiep , Le Quang Thao , Luu Manh Quynh , Le Viet Cuong , Nguyen Huy Tiep , Duc Thang Pham , Hoang Nam Nhat , Ngoc Dinh Nguyen","doi":"10.1016/j.omx.2024.100362","DOIUrl":"10.1016/j.omx.2024.100362","url":null,"abstract":"<div><div>SiO<sub>2</sub> opal crystals decorated with silver nanoparticles (AgNPs) have been successfully fabricated. SEM analysis revealed that the SiO<sub>2</sub> opals have an ordered region of 25–30 μm<sup>2</sup>, and AgNPs are located into the gaps between the SiO<sub>2</sub> nanospheres. The effect of the plasmons of AgNPs on the photoluminescence of SiO<sub>2</sub> opal crystals were investigated. Under excitation of a 325 nm laser, we observed the quenching of the intrinsic defect emission in SiO<sub>2</sub> as the concentration of AgNPs increased. The cause of the observed photoluminescence behavior is attributed to the interaction between surface plasmon induced by AgNPs and photoluminescence centers in SiO<sub>2</sub> opal crystals. Then, we utilized SiO<sub>2</sub> opals crystals decorated with AgNPs as a SERS substrate. The final enhancement factor of the Raman shift was 1.64 × 10<sup>7</sup>, enabling the trace detection limit for a case of malachite green to be as low as 0.05 ppm, with a relative standard deviation of less than 1.75 %. This outcome suggests the potential for direct application of the prepared substrates in ultra-fast chemical analysis.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100362"},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419612","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}
Pub Date : 2024-09-27DOI: 10.1016/j.omx.2024.100365
M.D. Moull , J.B.L. Martin , T.G.M. Newman , A.L. Jeffery , J.G. Bartholomew , J.-P.R. Wells , M.F. Reid
Erbium ions in crystals show considerable promise for the technologies that will form the backbone of future networked quantum information technology. Despite advances in leveraging erbium’s fibre-compatible infrared transition for classical and quantum applications, the transitions are, in general, not well understood. We present detailed absorption and laser site-selective spectroscopy of the C(O) centre in CaF:Er as an interesting erbium site case study. The 4IZIY transition has a low-temperature inhomogeneous linewidth of 1 GHz with hyperfine structure observable from the 167Er isotope. A parametrized crystal-field Hamiltonian is fitted to 34 energy levels and the two ground state magnetic splitting factors. The wavefunctions are used to perform a transition intensity analysis and electric-dipole parameters are fitted to absorption oscillator strengths. Simulated spectra for the 4II and 4II inter-multiplet transitions are in excellent agreement with the experimentally measured spectra. The 4I excited state lifetime is 25.0 ms and the intensity calculation is in excellent agreement with this value.
{"title":"Spectroscopy, crystal-field, and transition intensity analyses of the C3v(O2−) centre in Er3+ doped CaF2 crystals","authors":"M.D. Moull , J.B.L. Martin , T.G.M. Newman , A.L. Jeffery , J.G. Bartholomew , J.-P.R. Wells , M.F. Reid","doi":"10.1016/j.omx.2024.100365","DOIUrl":"10.1016/j.omx.2024.100365","url":null,"abstract":"<div><div>Erbium ions in crystals show considerable promise for the technologies that will form the backbone of future networked quantum information technology. Despite advances in leveraging erbium’s fibre-compatible infrared transition for classical and quantum applications, the transitions are, in general, not well understood. We present detailed absorption and laser site-selective spectroscopy of the C<span><math><msub><mrow></mrow><mrow><mi>3v</mi></mrow></msub></math></span>(O<span><math><msup><mrow></mrow><mrow><mn>2</mn><mo>−</mo></mrow></msup></math></span>) centre in CaF<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>:Er<span><math><msup><mrow></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> as an interesting erbium site case study. The <sup>4</sup>I<span><math><msub><mrow></mrow><mrow><mn>15</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span>Z<span><math><mrow><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub><msup><mrow><mo>→</mo></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span>I<span><math><msub><mrow></mrow><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span>Y<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> transition has a low-temperature inhomogeneous linewidth of 1 GHz with hyperfine structure observable from the <sup>167</sup>Er isotope. A parametrized crystal-field Hamiltonian is fitted to 34 energy levels and the two ground state magnetic splitting factors. The wavefunctions are used to perform a transition intensity analysis and electric-dipole parameters are fitted to absorption oscillator strengths. Simulated spectra for the <sup>4</sup>I<span><math><mrow><msub><mrow></mrow><mrow><mn>11</mn><mo>/</mo><mn>2</mn></mrow></msub><msup><mrow><mo>→</mo></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span>I<span><math><msub><mrow></mrow><mrow><mn>15</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> and <sup>4</sup>I<span><math><mrow><msub><mrow></mrow><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub><msup><mrow><mo>→</mo></mrow><mrow><mn>4</mn></mrow></msup></mrow></math></span>I<span><math><msub><mrow></mrow><mrow><mn>15</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> inter-multiplet transitions are in excellent agreement with the experimentally measured spectra. The <sup>4</sup>I<span><math><msub><mrow></mrow><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> excited state lifetime is 25.0<!--> <!-->ms and the intensity calculation is in excellent agreement with this value.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100365"},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419613","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}
Pub Date : 2024-09-26DOI: 10.1016/j.omx.2024.100367
Inesh E. Kenzhina , Artem L. Kozlovskiy , Aktolkyn Tolenova , Meiram Begentayev , Saulet Askerbekov
The key problem of using lithium-containing ceramics as materials of breeders for the propagation of tritium in thermonuclear reactors is phase stability, as well as the preservation of strength and thermophysical parameters of ceramics during their operation, which is accompanied by the accumulation of fission products in the near-surface layers, alongside mechanical influences from the outside. Moreover, in contrast to other types of ceramics, the presence of lithium in the composition of the samples under study leads to limitations in the use of classical analysis methods (scanning electron microscopy, energy dispersive analysis or optical spectroscopy) of structural changes caused by the accumulation of radiation damage, which requires the use of more complex methods for the assessment of the defect concentration in the structure, as well as establishing their relationship with the deterioration of strength and thermophysical parameters, playing a key role in determining the stability mechanisms and further exploitation of ceramics for tritium production. In this regard, the aim of the study is to determine the kinetics of changes in the near-surface layer of two-phase Li4SiO4 – Li2TiO3 ceramics associated with the accumulation of structural distortions caused by irradiation, as well as their relationship with strain embrittlement and disorder. During the studies, it was found that the accumulation of implanted hydrogen in the near-surface layer under high-dose irradiation initiates deformation distortion processes, the intensity of which depends on the ratio of components in the ceramics, according to which the optimal compositions of two-phase ceramics are ratios of components from 0.3 to 0.6. Determination of the type of defects in the composition of the damaged layer, as well as their concentration, was carried out using the electron spin resonance (ESP) method. During the studies, it was found that at low irradiation fluences, the dominant role in the accumulation of structural defects is played by vacancy defects associated with E′-centers, the formation of which is associated with structural distortions, while as the fluence grows, the structure is dominated by deformation disordering caused by the accumulation of Ti3+ defects and HC2 centers (SiO43-), the concentrations of which have a clear dependence on the phase composition of the ceramics.
{"title":"The connection between the accumulation of structural defects caused by proton irradiation and the destruction of the near-surface layer of Li4SiO4 – Li2TiO3 ceramics","authors":"Inesh E. Kenzhina , Artem L. Kozlovskiy , Aktolkyn Tolenova , Meiram Begentayev , Saulet Askerbekov","doi":"10.1016/j.omx.2024.100367","DOIUrl":"10.1016/j.omx.2024.100367","url":null,"abstract":"<div><div>The key problem of using lithium-containing ceramics as materials of breeders for the propagation of tritium in thermonuclear reactors is phase stability, as well as the preservation of strength and thermophysical parameters of ceramics during their operation, which is accompanied by the accumulation of fission products in the near-surface layers, alongside mechanical influences from the outside. Moreover, in contrast to other types of ceramics, the presence of lithium in the composition of the samples under study leads to limitations in the use of classical analysis methods (scanning electron microscopy, energy dispersive analysis or optical spectroscopy) of structural changes caused by the accumulation of radiation damage, which requires the use of more complex methods for the assessment of the defect concentration in the structure, as well as establishing their relationship with the deterioration of strength and thermophysical parameters, playing a key role in determining the stability mechanisms and further exploitation of ceramics for tritium production. In this regard, the aim of the study is to determine the kinetics of changes in the near-surface layer of two-phase Li<sub>4</sub>SiO<sub>4</sub> – Li<sub>2</sub>TiO<sub>3</sub> ceramics associated with the accumulation of structural distortions caused by irradiation, as well as their relationship with strain embrittlement and disorder. During the studies, it was found that the accumulation of implanted hydrogen in the near-surface layer under high-dose irradiation initiates deformation distortion processes, the intensity of which depends on the ratio of components in the ceramics, according to which the optimal compositions of two-phase ceramics are ratios of components from 0.3 to 0.6. Determination of the type of defects in the composition of the damaged layer, as well as their concentration, was carried out using the electron spin resonance (ESP) method. During the studies, it was found that at low irradiation fluences, the dominant role in the accumulation of structural defects is played by vacancy defects associated with E′-centers, the formation of which is associated with structural distortions, while as the fluence grows, the structure is dominated by deformation disordering caused by the accumulation of Ti<sup>3+</sup> defects and HC<sub>2</sub> centers (SiO<sub>4</sub> <sup>3-</sup>), the concentrations of which have a clear dependence on the phase composition of the ceramics.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100367"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356638","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}
Pub Date : 2024-09-26DOI: 10.1016/j.omx.2024.100368
U. Rogulis, A. Fedotovs, Dz Berzins, G. Krieke, L. Skuja, A. Antuzevics
A study was conducted to examine the recombination processes in persistent phosphor Mg3Y2Ge3O12:Tb3+ garnet at low temperatures. Photoluminescence (PL), recombination luminescence (RL), electron paramagnetic resonance (EPR), and EPR detected by PL or RL were measured.
In samples with low Tb3+ concentration, a broad PL and RL band around 400–450 nm and characteristic Tb3+ lines were observed. However, in samples with high Tb3+ concentration, only Tb3+ lines were present. Both the broad-band and the line components exhibit long-lasting tunneling luminescence with hyperbolic decay. After 263 nm UV irradiation signals of intrinsic electron (F-type) and hole (V-type) trapping centres were observed in the EPR spectra. Such signals were also observed in RL-detected EPR spectra, indicating that the broad RL band at low Tb3+ concentrations originates from tunneling recombination between these intrinsic traps. At high Tb3+ concentrations, the RL-EPR spectrum was not observed, suggesting that intrinsic electron and Tb-related hole trapping centres probably participate in the tunneling recombination.
{"title":"Low temperature recombination luminescence of Mg3Y2Ge3O12:Tb3+","authors":"U. Rogulis, A. Fedotovs, Dz Berzins, G. Krieke, L. Skuja, A. Antuzevics","doi":"10.1016/j.omx.2024.100368","DOIUrl":"10.1016/j.omx.2024.100368","url":null,"abstract":"<div><div>A study was conducted to examine the recombination processes in persistent phosphor Mg<sub>3</sub>Y<sub>2</sub>Ge<sub>3</sub>O<sub>12</sub>:Tb<sup>3+</sup> garnet at low temperatures. Photoluminescence (PL), recombination luminescence (RL), electron paramagnetic resonance (EPR), and EPR detected by PL or RL were measured.</div><div>In samples with low Tb<sup>3+</sup> concentration, a broad PL and RL band around 400–450 nm and characteristic Tb<sup>3+</sup> lines were observed. However, in samples with high Tb<sup>3+</sup> concentration, only Tb<sup>3+</sup> lines were present. Both the broad-band and the line components exhibit long-lasting tunneling luminescence with hyperbolic decay. After 263 nm UV irradiation signals of intrinsic electron (F-type) and hole (V-type) trapping centres were observed in the EPR spectra. Such signals were also observed in RL-detected EPR spectra, indicating that the broad RL band at low Tb<sup>3+</sup> concentrations originates from tunneling recombination between these intrinsic traps. At high Tb<sup>3+</sup> concentrations, the RL-EPR spectrum was not observed, suggesting that intrinsic electron and Tb-related hole trapping centres probably participate in the tunneling recombination.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100368"},"PeriodicalIF":0.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356636","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}
In this study, YOF:Pr3+ nanophosphors were synthesized using the microwave-assisted hydrothermal route. The structural and morphological properties of the nanophosphors calcined at different temperatures were studied in detail to optimize the synthesis conditions. The visible region and near-infrared (NIR) photoluminescence (PL) properties of the nanophosphors were obtained. Intense emission bands were observed in the blue and red regions under 250 nm excitation. The CIE chromaticity diagram showed that the color coordinates of the nanophosphors were located in the yellow region. The optimum Pr3+-concentration was found to be 0.002 mol fraction. The application of YOF: 0.002 Pr3+ nanophosphor for latent fingerprint detection was examined and evaluated on different types of surfaces. The nanophosphor demonstrated excellent adherence to the ridge patterns and sufficient sensitivity required for distinguishing between the ridges and the furrows. Different levels of detail were also observed that provided necessary information for the individualization of the fingerprints. The results suggest that the prepared YOF:Pr3+ nanophosphor can be a potential candidate for the rapid visualization and detection of latent fingerprints.
{"title":"Latent fingerprint detection and identification using yellow-emitting YOF:Pr3+ nanophosphor","authors":"Sumedha Tamboli , Govind B. Nair , S.J. Dhoble , H.C. Swart","doi":"10.1016/j.omx.2024.100364","DOIUrl":"10.1016/j.omx.2024.100364","url":null,"abstract":"<div><div>In this study, YOF:Pr<sup>3+</sup> nanophosphors were synthesized using the microwave-assisted hydrothermal route. The structural and morphological properties of the nanophosphors calcined at different temperatures were studied in detail to optimize the synthesis conditions. The visible region and near-infrared (NIR) photoluminescence (PL) properties of the nanophosphors were obtained. Intense emission bands were observed in the blue and red regions under 250 nm excitation. The CIE chromaticity diagram showed that the color coordinates of the nanophosphors were located in the yellow region. The optimum Pr<sup>3+</sup>-concentration was found to be 0.002 mol fraction. The application of YOF: 0.002 Pr<sup>3+</sup> nanophosphor for latent fingerprint detection was examined and evaluated on different types of surfaces. The nanophosphor demonstrated excellent adherence to the ridge patterns and sufficient sensitivity required for distinguishing between the ridges and the furrows. Different levels of detail were also observed that provided necessary information for the individualization of the fingerprints. The results suggest that the prepared YOF:Pr<sup>3+</sup> nanophosphor can be a potential candidate for the rapid visualization and detection of latent fingerprints.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100364"},"PeriodicalIF":0.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326520","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}
During electron beam evaporation of green-emitting (λex = 980 nm) silicate upconversion (UC-PL) bulk phosphors Sr2Y6.8YbEr0.2Si6O26, amorphous nanoparticles of size 2.7 nm are formed. The nanoparticles are globules formed during condensation of chains consisting of SiO4 tetrahedra. When the globules are excited with radiation of λex = 980 nm, the luminescence color becomes red and its intensity increases 80 times compared with bulk phosphors. It has been shown that luminescence is influenced by nonradiative processes between different transitions of Er3+ ions. There is a threshold population of the Er3+ and Yb3+ levels (level 2F5/2) in the region of relatively low pumping powers. Above this threshold, a sharp increase in the intensity of upconversion photoluminescence occurs. We show that the produced nanophosphors have a core consisting of a combination of SiO tetrahedra (n = 0, 1, 2), while Er, Yb, Sr, and Y ions are on the surface of the globules. Owing to this structure of the globules, the interaction of Er and Yb ions with nucleus defects, which usually suppress the luminescence, decreases. Probably, for this reason the luminescence intensity increases. Our findings reveal that new effective non-linear materials can be designed for converting IR radiation into visible radiation. The produced effective phosphors can hold promise as fluorescent probes in bioresearch, for fundamental therapy, as well as for new display technologies.
{"title":"Threshold phenomena in photoluminescence of upconversion micro- and nanophosphors containing Er3+ and Yb3+ ions","authors":"M.G. Zuev , V.G. Il'ves , S.Yu. Sokovnin , A.A. Vasin , E.Yu. Zhuravleva","doi":"10.1016/j.omx.2024.100363","DOIUrl":"10.1016/j.omx.2024.100363","url":null,"abstract":"<div><div>During electron beam evaporation of green-emitting (λ<sub>ex</sub> = 980 nm) silicate upconversion (UC-PL) bulk phosphors Sr<sub>2</sub>Y<sub>6.8</sub>YbEr<sub>0.2</sub>Si<sub>6</sub>O<sub>26</sub>, amorphous nanoparticles of size 2.7 nm are formed. The nanoparticles are globules formed during condensation of chains consisting of SiO<sub>4</sub> tetrahedra. When the globules are excited with radiation of λ<sub>ex</sub> = 980 nm, the luminescence color becomes red and its intensity increases 80 times compared with bulk phosphors. It has been shown that luminescence is influenced by nonradiative processes between different transitions of Er<sup>3+</sup> ions. There is a threshold population of the Er<sup>3+</sup> and Yb<sup>3+</sup> levels (level <sup>2</sup><em>F</em><sub>5/2</sub>) in the region of relatively low pumping powers. Above this threshold, a sharp increase in the intensity of upconversion photoluminescence occurs. We show that the produced nanophosphors have a core consisting of a combination of SiO tetrahedra (n = 0, 1, 2), while Er, Yb, Sr, and Y ions are on the surface of the globules. Owing to this structure of the globules, the interaction of Er and Yb ions with nucleus defects, which usually suppress the luminescence, decreases. Probably, for this reason the luminescence intensity increases. Our findings reveal that new effective non-linear materials can be designed for converting IR radiation into visible radiation. The produced effective phosphors can hold promise as fluorescent probes in bioresearch, for fundamental therapy, as well as for new display technologies.</div></div>","PeriodicalId":52192,"journal":{"name":"Optical Materials: X","volume":"24 ","pages":"Article 100363"},"PeriodicalIF":0.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356635","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}
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