Browsing by Department "Fraunhofer-Einrichtung für Wertstoffkreisläufe und Ressourcenstrategie IWKS"
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Publication3D Analogs of Square-Net Nodal Line Semimetals( 2022)
;Teicher, S.M.L. ;Linnartz, J.F. ;Singha, R. ;Pizzirani, D. ;Wiedmann, S. ;Cano, J.Schoop, L.M.In two-dimensional (2D) systems, the origins of topological band structure have been linked to simple chemical bonding models. Here, we investigate the three-dimensional (3D) metal LaIn3 and show that its electronic structure and band topology are well-modeled using a tight-binding model consisting of only In p orbitals. We predict this material to be a nodal line semimetal with Dirac crossings and topological surface states at the experimental Fermi level. This compound can be considered a 3D chemical analog of 2D square-net semimetals in the ZrSiS family, with primary px,y orbital contributions and cubic connectivity. LaIn3 and related auricupride metals are established superconductors and may provide a valuable platform for exploring the interplay between the topological electronic structure and superconductivity. -
PublicationA Combined Hydro-Mechanical and Pyrometallurgical Recycling Approach to Recover Valuable Metals from Lithium-Ion Batteries Avoiding Lithium Slagging( 2023)
;Holzer, Alexandra ;Wiszniewski, Lukas ;Necke, Tobias ;Gatschlhofer, Christoph ;Öfner, WolfgangRaupenstrauch, HaraldMeeting the increasing demand for energy storage based on lithium-ion batteries (LIB) is not only a question of resource availability but also an issue of resource conservation and efficient recycling management. In this respect, sustainable recycling concepts play a central role in mindful interactions with valuable materials. Based on this approach, a process interconnection of hydromechanical preparation, flotation, and pyrometallurgical treatment was investigated. The hydromechanical preparation showed promising results in achieving highly pure mixtures of LIB-active material. It was found that a pre-opening step could achieve an even better separation of impurities for downstream processes such as Cu and Al to avoid excessive particle size reduction. According to an optimized mixing stage during flotation, the C amount was reduced from 33 wt.% to 19.23 wt.%. A Li-free metal alloy was obtained through the subsequent pyrometallurgical treatment, and evidence for Li removal via the gas phase was provided. Furthermore, heating microscope trials confirmed the results of the process interconnection and showed that further optimization steps for the pre-treatment are necessary for favorable product quality. Therefore, a high-stratification plot was created, which allows a quick future statement about the suitability of the input material for use in the process. -
PublicationA facile strategy for reclaiming discarded graphite and harnessing the rate capabilities of graphite anodes( 2023)
;Tian, Honghong ;Graczyk-Zaja̧c, Magdalena J. ;Carolis, Dario M. de ;Tian, Chuanmu ;Ricohermoso, Emmanuel I.I.I. ;Yang, Zhiwu ;Li, Wei ;Wilamowska-Zawlocka, Monika ;Hofmann, Jan PhilippRiedel, Ralf R.Graphite negative electrodes are unbeaten hitherto in lithium-ion batteries (LiBs) due to their unique chemical and physical properties. Thus, the increasing scarcity of graphite resources makes smart recycling or repurposing of discarded graphite particularly imperative. However, the current recycling techniques still need to be improved upon with urgency. Herein a facile and efficient hydrometallurgical process is reported to effectively regenerate aged (39.5 %, 75 % state-of-health, SOH) scrapped graphite (SG) from end-of-life lithium-ion batteries. Ultimately, the first cycle reversible capacity of SG1 (SOH = 39.5 %) improved from 266 mAh/g to 337 mAh/g while 330 mAh/g (98 %) remain after 100 cycles at 0.5 C. The reversible capacity for the first cycle of SG2 (SOH = 75 %) boosted from 335 mAh/g to 366 mAh/g with the capacity retention of 99.3 % after 100 cycles at 0.5 C, which is comparable with the benchmark commercial graphite. The regenerated graphites RG1 and RG2 exhibit excellent output characteristics even increasing the rate up to 4 C. This is the best rate level reported in the literature to date. Finally, the diffusion coefficient of Li ions during deintercalation and intercalation in the regenerated graphites have been measured by galvanostatic intermittent titration technique (GITT), determining values 2 orders-of-magnitude higher than that of the spent counterparts. Taking advantage of the synergistic effect of acid leaching and heat treatment, this strategy provides a simple and up-scalable method to recycle graphitic anodes. -
PublicationAdditive manufacturing of ceramic materials for energy applications: Road map and opportunities( 2022)
;Cramer, C.L. ;Graczyk-Zajac, M. ;Nelson, A.T. ;Katoh, Y. ;Haslam, J.J. ;Wondraczek, L. ;Aguirre, T.G. ;LeBlanc, S. ;Wang, H. ;Masoudi, M. ;Tegeler, E. ;Riedel, R. ;Colombo, P.Minary-Jolandan, M.Among engineering materials, ceramics are indispensable in energy applications such as batteries, capacitors, solar cells, smart glass, fuel cells and electrolyzers, nuclear power plants, thermoelectrics, thermoionics, carbon capture and storage, control of harmful emission from combustion engines, piezoelectrics, turbines and heat exchangers, among others. Advances in additive manufacturing (AM) offer new opportunities to fabricate these devices in geometries unachievable previously and may provide higher efficiencies and performance, all at lower costs. This article reviews the state of the art in ceramic materials for various energy applications. The focus of the review is on material selections, processing, and opportunities for AM technologies in energy related ceramic materials manufacturing. The aim of the article is to provide a roadmap for stakeholders such as industry, academia and funding agencies on research and development in additive manufacturing of ceramic materials toward more efficient, cost-effective, and reliable energy systems. -
PublicationAdditive manufacturing of Ni-Mn-Sn shape memory Heusler alloy - Microstructure and magnetic properties from powder to printed parts( 2023)
;Scheibel, Franziska ;Lauhoff, Christian ;Krooß, P. ;Riegg, Stefan ;Sommer, Niklas ;Koch, David ;Gutte, Heiner ;Volkova, Olena ;Böhm, Stefan ;Niendorf, ThomasGutfleisch, OliverNi-Mn-based Heusler alloys such as Ni-Mn-Sn show both elastocaloric and magnetocaloric effects during the magneto-structural phase transition, making these materials interesting for solid-state cooling applications. Material processing by additive manufacturing can overcome difficulties related to the machinability of the alloys, caused by their intrinsic brittleness. Since the magnetic properties and transition temperature are highly sensitive to the chemical composition, it is essential to understand and monitor these properties over the entire processing chain. In the present work, the microstructural and magnetic properties from gas-atomized powder to post-processed Ni-Mn-Sn alloy are investigated. Directed energy deposition was used for processing, promoting the evolution of a polycrystalline microstructure being characterized by elongated grains along the building direction. A complete and sharp martensitic transformation can be achieved after applying a subsequent heat treatment at 1173 K for 24 h. The Mn-evaporation of 1.3 at.% and the formation of Mn-oxide during DED-processing lead to an increase of the transition temperature of 21 K and a decrease of magnetization, clearly pointing at the necessity of controlling the composition, oxygen partial pressure and magnetic properties over the entire processing chain. -
PublicationAnomalous thermal conductivity of alkaline-earth-metal-substituted EuTiO3 induced by resonant scattering( 2023)
;Xiao, Xingxing ;Xie, Wenjie ;Philippi, Kai ;Liu, Yamei ;Skokov, Konstantin P. ;Radulov, Iliya Angelov ;Widenmeyer, Marc ;Kovalevsky, Andrei V. ;Shen, Chen ;Zhang, Hongbin ;Checchia, Stefano ;Scavini, Marco ;He, JianWe have investigated thermal conductivities (κ) of polycrystalline Eu1–xAxTiO3 (A = Ca, Sr, Ba, 0 ≤ x ≤ 0.8) bulk materials in the temperature range of ∼ 2 K < T < 1173 K. The EuTiO3 demonstrates anomalous glass-like κ(T) behavior at low temperatures. Partial substitutions with Sr2+ and Ba2+ do not cause a significant change in the κ(T) behavior, while a κ(T) peak, which looks like a manifestation of a typical crystalline solid, appears only in the Ca-substituted samples with an orthorhombic structure when x ≥ 0.4. After excluding the magnetic effects on κ and discussing the possible phonon scattering mechanisms in depth, together with heat capacity Cp measurements and high-resolution X-Ray diffraction characterization, we find that the unusual low κ at low temperatures is attributed to resonant scattering induced by the intrinsic disordered local structure and lattice instability in EuTiO3. Due to the different lattice dynamics of ATiO3, the lattice structure of Eu1–xCaxTiO3 can be regarded as formed by a part-soft (from EuTiO3) part-rigid (from CaTiO3) sublattice. The anomalous κ(T) behavior of Eu1–xCaxTiO3 results from the combined effect of phonon transport between the normal phononic heat transport in the rigid sublattice and the strong damping of heat conduction in the soft sublattice. -
PublicationAuthor Correction: Fabrication of phosphor in glass using waste glass for automotive lighting application (Scientific Reports, (2023), 13, 1, (4456), 10.1038/s41598-023-27685-2)( 2023)
;Choi, Seung-hee ;Kwon, Seok-bin ;Yoo, Junghyeon ;Na, Minyoung ;Kim, Bo-young ;Yoon, Ho-shin ;Park, Seounghyok ;Kang, Bongkyun ;Yoon, DaehoSong, YounghyunIn the original version of this article Seung Hee Choi, Bo Young Kim and Young Hyun Song were incorrectly affiliated with ‘Mobility Lighting Research Center, Korea Photonics Technology Institute, Gwangju, 61007, Republic of Korea’. The correct affiliation is listed below. Lighting Materials & Components Research Center, Korea Photonics Technology Institute, Gwangju 61007, Republic of Korea. The original Article has been corrected. -
PublicationBiogas reforming for hydrogen-rich syngas production over a Ni-K/Al2O3 catalyst using a temperature-controlled plasma reactor( 2023)
;Zeng, Y. ;Bai, Q. ;Wang Hongli, L. ;Wu, R.Tu, X.Plasma-enhanced catalytic biogas reforming for hydrogen-rich syngas production over a Ni-K/Al2O3 catalyst was investigated using a tabular dielectric barrier discharge non-thermal plasma reactor. To better understand the plasma catalysis synergy at elevated temperatures, we compared different reaction modes: plasma catalysis, plasma alone, and catalysis alone in a reaction temperature range of 160-400 °C. The combination of Ni-K/Al2O3 and plasma produced synergistic effects. Notably, the plasma-catalytic synergy was temperature-dependent and varied at different reaction temperatures. Using plasma catalysis, the maximum conversion of CH4 and CO2 (31.6% and 22.8%, respectively) was attained over Ni-K/Al2O3 at 160 °C, while increasing the reaction temperature to 340 °C noticeably enhanced the H2/CO ratio to 2.71. Moreover, compared to plasma-catalytic biogas reforming at 160 °C, increasing the reaction temperature to 400 °C suppressed biogas conversion with dramatically reduced coke formation on the Ni–K/Al2O3 surface from 6.81 wt% to 3.37 wt%. -
PublicationCatalytic ignition of CO over CuCeZr based catalysts: New insights into the support effects and reaction pathways( 2023)
;Kang, Running ;Zhang, Zirui ;Bin, Feng ;Wei, Xiaolin ;Li, YongdanTu, XinSelf-sustained catalytic combustion is a promising strategy to remove CO from the off-gas produced during steelmaking, where the potential catalysts are bulk copper-cerium-zirconium mixed oxides or those supported on TiO2 or ZSM-5 substrates. In this study, the effects of the catalyst support on the CO catalytic ignition performance and reaction pathways were investigated by FTIR coupled with a novel in-situ cell, together with the state-of-the-art characterization techniques. The Infrared (IR) transmission cell equipped with a magnetically driven system, could effectively prevent overlaps between active intermediate peaks (Cu+-CO and Cu+(CO)2) and gaseous CO peaks. The Cu+ cations located at the phase interface are the main active sites. The Cu and Ce interactions lead to the formation of solid solutions of CuCe0.75Zr0.25Oδ (CuCeZr). The monocarbonyls [Cu+-CO] are the dominant species during CO oxidation, and the vacancies in the solid solutions are occupied by oxygen, accelerating the oxygen cycle. The TiO2 or ZSM-5 supports promote copper dispersion over CuCe0.75Zr0.25Oδ/TiO2 (CuCeZr/T) and CuCe0.75Zr0.25Oδ/ZSM-5 (CuCeZr/Z) catalysts, which can be attributed to their high surface areas (168.2 and 346.3 m2/g, respectively), while the Cu-Ce interactions are less relevant. Hence, CO oxidation mainly occurs at the phase interface between copper oxide and TiO2/ZSM-5. Dicarbonyls [Cu+(CO)2] are the main intermediates for the CuCeZr/T and CuCeZr/Z catalysts, and the Cu2+ species are reduced to form dicarbonyls that also take part in the oxidation process. Although a well copper dispersion enhances the activity of individual copper sites on the CuCeZr/T and CuCeZr/Z catalysts, considering the redshift of the carbonyl bands and the increase in CO adsorption, the close interactions and high contents of Cu and Ce favor the local accumulation of heat and mass transfer over bulk CuCeZr, leading to the ignition of CO at low temperatures. -
PublicationCatalytic recycling of medical plastic wastes over La0.6Ca0.4Co1-xFexO3-δ pre-catalysts for co-production of H2 and high-value added carbon nanomaterials( 2023)
;Yu, Xiao ;Widenmeyer, Marc ;Liu, Xingmin ;Kunz, Ulrike ;Schüpfer, Dominique ;Molina-Luna, Leopoldo ;Tu, XinIn this work, waste medical masks collected from daily life usage were pyrolyzed and catalytically decomposed with perovskite-type La0.6Ca0.4Co1-xFexO3-δ pre-catalysts for co-production of carbon nanomaterials and H2. The influences of catalysis reaction temperature and Co/Fe ratio in the investigated pre-catalysts on the yields and selectivity of the gaseous products and carbon deposition were systematically studied. The physicochemical characteristics of the produced carbon nanomaterials were comprehensively characterized by the state-of-the-art techniques. La0.6Ca0.4Co0.2Fe0.8O3-δ possessed the highest hydrogen and carbon nanomaterials yields at 850 °C among all the investigated pre-catalysts. Especially, this pre-catalyst showed an excellent performance during the 10 cycles of successive deconstruction of plastic wastes with the highest hydrogen yield of 34.33 mmol / gplastic at the 7th cycle. More importantly, carbon nanotubes generated had higher graphitic characteristics and fewer defects. The presented results demonstrated that the developed perovskite-type pre-catalyst is a promising candidate for the production of hydrogen and carbon nanotube composites for energy storge applications from medical waste plastics. -
PublicationChemical Stability and Hydrogen Reaction Behavior of SmCo 2:17-Type Permanent Magnets( 2023)
;Betz, Stefan ;Metzmacher, Christoph ;Yoon, SonghakHerein, the reaction behavior and chemical stability of two commercially available SmCo 2:17-type sintered magnets with nominal composition of Sm23.75Co48.67FebalCu4.91Zr2.37 and Sm24.95Co48.80FebalCu4.46Zr2.68 (wt%) are investigated. The magnets are placed in a hydrogen atmosphere with systematically varied pressure, exposure time, and temperature ranging from 1-11 bar, 2-10 d, and 25-500 °C, respectively. Hydrogen content, magnetic properties, microstructure, and lattice constants are characterized in detail. It is found that for short exposure times like 2 d an activation temperature of 120 °C is necessary to initiate the reaction and to increase the amount of hydrogen in the Sm-Co material. Hydrogen absorption starts at lower temperatures with longer exposure times. An increase in exposure time, temperature, or pressure leads to a higher hydrogen content and a decrease in remanence Br, energy product (BH)max, and coercivity HcB. Lattice expansion, estimated by X-ray diffraction analysis, correlates with the increasing amount of hydrogen in the Sm-Co magnets. With respect to all varied parameters under investigation, the exposure temperature has the highest impact on the observed property changes followed by reaction time and H2 pressure. -
PublicationControlling the Defects of Cs2AgBiBr6 by Varied Precursor Compositions( 2022)
;Frebel, Alexander ;Yoon, Song Hak ;Jöckel, Dennis Michael ;Widenmeyer, Marc ;Lange, Stefan ;Naumann, Volker ;Rosspeintner, Arnulf ;Ebbinghaus, Stefan G.The amount and type of defects in Cs2AgBiBr6 are controlled by varying the Ag/Bi ratio of the precursor solutions in two different synthesis routes, that is, slow solution cooling crystallization and fast microwave-assisted hydrothermal synthesis. The correlation between the Ag/Bi ratio in the precursor solution and defect formation in the crystals is studied by band broadening analysis in Raman spectroscopy, the estimated Urbach energy in UV-vis spectroscopy, and thermogravimetric analysis. Ag-rich precursors are found to prevent the formation of the secondary-phase Cs3Bi2Br9, but at the same time induced the formation of Br vacancies and antisite defects. Time-resolved photoluminescence measurements reveal that the formation of beneficial defects such as Br vacancies causes to trap the charge carriers, thus avoiding the recombination of charge carriers and leading to a longer carrier lifetime. Herein, the findings provide a guidance to decrease the defect densities and can be applied to the fabrication of Pb-free solar cells based on Cs2AgBiBr6. -
PublicationCorrigendum to "Screening for sustainable and lead-free perovskite halide absorbers - A database collecting insight from electronic-structure calculations” [Mater. & Des. 234 (2023) 112324]( 2024)
;Gebhardt, JulianElsässer, Christian"In the list of authors the second affiliation of the third author Wei Wei is missing. The correct affiliation is Wei Wei." The authors apologise for the mistake. -
PublicationDefect structures and dopant solution states of Hf-doped Si3N4 ceramics( 2023)
;Kuwabara, Akihide ;Gao, Xiang ;Riedel, Ralf R.Ikuhara, YuichiTransition-metal-doped silicon nitride ceramics have attracted much attention as gate materials for semiconductors because of their electrical properties as well as chemical and thermal stability. The present study aims to clarify the defect structures of Hf-doped β-Si3N4 by theoretical calculations and scanning transmission electron microscopy (STEM). First-principles calculations based on a hybrid functional method were performed. It was found that Hf dopants are mainly substituted for the Si sites and can be occasionally located at interstitial sites in the lattice of β-Si3N4. The substitution sites of Hf dopants predicted by the first-principles calculations were also confirmed by the high-resolution STEM images. -
PublicationEffect of ultra-fast pyrolysis on polymer-derived SiOC aerogels and their application as anodes for Na-ion batteries( 2023)
;Melzi D'Eril, Marco ;Zambotti, Andrea ;Graczyk-Zaja̧c, Magdalena J. ;Sorarù, Gian DomenicoRiedel, Ralf R.In the last decade, Sodium-Ion-Batteries (SIB) started to gain interest as a possible complementary candidate to support the overburdened lithium technology, but the manufacturing of a proper anode material is one of the challenging factors for the development of performing SIB. Among others, porous polymer-derived ceramics have been widely explored as suitable anodes despite the production of such materials being time and energy-consuming. In this work, we investigate the feasibility of adopting a low-cost ultra-fast high-temperature pyrolysis for the ceramic conversion of a polymer-derived SiOC aerogel to be employed as anode material. A comprehensive study including N2 physisorption, 29Si MAS NMR and Raman spectroscopy provides the insights of the effect of ultra-fast and conventional heating rates (i.e., 200 °C·s-1 vs. 5 °C·min-1) on the microstructural features and ceramic yield of the SiOC aerogels. As a consequence of the ultra-fast heating rate, a compositional drift towards oxygen-rich SiOC is observed and discussed. The electrochemical performance of both ceramics has been tested and related to the observed compositional differences, revealing a stable capacity of 103 mAh·g-1 for the ultra-fast pyrolyzed SiOC anode, and 152 mAh·g-1 for SiOC ceramized at 5 °C·min-1. -
PublicationEnhanced hydrogen production using a tandem biomass pyrolysis and plasma reforming process( 2022)
;Wang, W. ;Ma, Y. ;Quan, C. ;Yanik, J. ;Gao, N.Tu, X.Converting biomass into energy and fuels is considered a promising strategy for replacing the exhaustible fossil fuels. In this study, we report on a tandem process that combines cellulose pyrolysis and plasma-assisted reforming for H2 production. The hybrid pyrolysis/plasma reforming process was carried out in a two-stage reaction system incorporating a coaxial dielectric barrier discharge (DBD) plasma reactor. The effects of discharge power, steam, reforming temperature, and catalyst on the reaction performance were investigated. The results show that low temperatures are preferred in the non-catalytic plasma reforming process, whereas high temperatures are desired to achieve a high H2 yield and a high H2 selectivity in the plasma-catalytic reforming system. The synergistic effect of plasma catalysis was dominant in the plasma-catalytic reforming process at 250 °C. In contrast, the catalyst, rather than the plasma, played a dominant role in the plasma-catalytic reforming at higher temperatures (550 °C). Using Ni-Co/Al2O3 at a reforming temperature of 550 °C, a high H2 yield of 26.6 mmol/g was attainted, which was more than 8 times and about 100% greater than that obtained using plasma alone and catalyst alone, respectively. This work highlights the potential of non-thermal plasmas in low-temperature biomass conversion. -
PublicationEnzymatic Degradation of Fiber-Reinforced PLA Composite Material( 2022)
;Urinov, EldorApplication of thermoplastic fiber-reinforced lightweight composite materials provides a wide range of advantages that are of particular importance for the mobility sector. UD tapes composed of unidirectionally (UD) oriented inorganic fibers embedded in a thermoplastic matrix represent light-weight materials with high tensile strength. This publication addresses recycling aspects of novel UD tape made of a combination of basalt fibers and different PLA (polylactic acid) formulations. The kinetics of enzyme-based separation of polymer from the fiber were investigated. Different types of UD tapes with a thickness of 270-290 µm reinforced with basalt fiber weight ratios ranging between 51 and 63% were incubated at 37 °C in buffer solution (pH 7.4) containing proteinase K. The influence of enzyme concentration, tape weight per incubation tube, proteinase K activators, and tape types on the rate of enzymatic decomposition was investigated. Enzyme activity was measured by analyzing lactate concentration with lactate dehydrogenase and by measuring weight loss of the composite material. The rate of lactate release increased in the first 30 min of incubation and remained stable for at least 90 min. Weight loss of 4% within 4 h was achieved for a tape with 56% (w/w) fiber content. For a sample with a surface area of 3 cm2 in a buffer volume of 10 mL, the rate of lactate release as a function of enzyme concentration reached saturation at 300 µg enzyme/mL. With this enzyme concentration, the rate of lactate release increased in a linear manner for tape surface areas between 1 and 5 cm2. Four tapes with different PLA types were treated with the enzyme for 17 h. Weight loss ranged between 7 and 24%. Urea at a concentration of 0.5% (w/v) increased lactate release by a factor of 9. Pretreatment of tapes in alkaline medium before enzymatic degradation increased weight loss to 14% compared to 5% without pretreatment. It is concluded that enzymatic PLA hydrolysis from UD tapes is a promising technology for the release of basalt fibers after alkaline pretreatment or for the final cleaning of basalt fibers. -
PublicationErratum of the paper “Cr-substitution in Ba2In2O5(H2O)x (x = 0.16, 0.74)”( 2022)
;Yoon, Song Hak ;Son, K. ;Hagemann, H. ;Widenmeyer, M.1. Errors were found in Fig. 4 FT-IR spectra, and the interpretation for the respective Figure was corrected.2. The proposed chemical formula of Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y from determined water contents were updated.3. Errors were spotted in the reference list and corrected. It has been realized that the FT-IR spectra of Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y shown in Fig. 4 of the originally published paper had been assigned incorrectly. [1] Hence, given observation and data interpretation has not been correct either. The correction is given as following. FT-IR spectra of Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y are shown in corrected Fig. 4. The peaks at 871 and 2981 cm−1 are assigned to the vibrations of InO4 tetrahedra units and OH− stretching, respectively [19,20]. The peak at 1416 cm−1 is interpreted as the CO vibration of carbonate [32]. The peaks at 871 and 2981 cm−1 are significantly smaller for Ba2In2O5·(H2O)x. Additionally, characteristic small peaks of Ba2(In1.8Cr0.2)O5·(H2O)y in the wavenumber range of 1250 to 1050 cm−1 (small arrows in corrected Fig. 4) appear by Cr substitution. The original paragraph previously published was following. [1]. FT-IR spectra of Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y are shown in Fig. 4. The peaks at 871 and 2981 cm−1 are assigned to the vibrations of InO4 tetrahedra units and OH- stretching, respectively [19,20]. The peak at 1416 cm−1 is interpreted as the CO vibration of carbonate [32]. It can be seen that for Ba2(In1.8Cr0.2)O5·(H2O)y the peaks at 871 and 2980 cm−1 are significantly smaller, whereas the peak at around 1416 cm−1 is more pronounced compared to the pristine Ba2In2O5·(H2O)x. Additionally, characteristic small peaks of Ba2In2O5·(H2O)x in the wavenumber range of 1250 to 1050 cm−1 (small arrows in Fig. 6), completely vanished by Cr substitution. Corrected Fig. 4. Songhak Yoon et al. [Figure presented] Corrected Fig. 4. FT-IR spectra of (1) Ba2In2O5·(H2O)x and (2) Ba2(In1.8Cr0.2)O5·(H2O)y. Originally published Fig. 4. Songhak Yoon et al. [Figure presented] Fig. 4. FT-IR spectra of (1) Ba2In2O5·(H2O)x and (2) Ba2(In1.8Cr0.2)O5·(H2O)y. During the preparation of our recently published paper [2], we realized that the accurate estimation of the amount of water in Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y is not achievable from the mass change in thermogravimetric analysis. Combined analysis of magic angle spinning nuclear magnetic resonance (MAS-NMR) and powder neutron diffraction revealed that more than two different types of protons from hydroxyl groups and crystal water were found to be present. Therefore, our model chemical formula Ba2In2O5·(H2O)x and Ba2(In1.8Cr0.2)O5·(H2O)y [1] was too simple to be true. To be more accurate, the chemical formula should be Ba2In2O5-x·(OH)y·(H2O)z and the same should be applied to Cr-substituted sample. As discussed [2], accurate and precious estimation of lattice oxygen, hydroxyl ion, and crystal water may not be trivial. Nevertheless, estimated proton species are reported and sum formula would be Ba2In1.8Cr0.2O5.32(4)–x(OH)x(H2O)y for Cr-substituted sample[2]. [1] S. Yoon, K. Son, H. Hagemann, M. Widenmeyer, A. Weidenkaff, Cr-substitution in Ba2In2O5⋅(H2O)x (x = 0.16, 0.74), Solid State Sci. 73 (2017) 1–6, https://doi.org/10.1016/j.solidstatesciences.2017.08.019.[2] R. Finger, M. Widenmeyer, T. C. Hansen, D. Wallacher, S. Savvin, M. Bertmer, A. Weidenkaff, H. Kohlmann, Effects of Cr doping and water content on the crystal structure transitions of Ba2In2O5 Crystals 11 (2021) 1548, https://doi.org/10.3390/cryst11121548. Three errors and inaccuracies in the reference lists were found from the originally published paper. Those need to be corrected and listed in the following. Previous) [8] J. Bielecki, S.F. Parker, L. Mazzei, L. Börjesson, M. Karlsson, J. Mater. Chem. A. 4 (2016).Corrected) [8] J. Bielecki, S.F. Parker, L. Mazzei, L. Börjesson, M. Karlsson, J. Mater. Chem. A. 4 (2016) 1224–1232Previous) [10] A. Jarry, O. Joubert, E. Suard, J.-M. Zanotti, E. Quarez, Phys. Chem. Chem. Phys. (2016) 25–30.Corrected) [10] A. Jarry, O. Joubert, E. Suard, J.-M. Zanotti, E. Quarez, Phys. Chem. Chem. Phys. 18 (2016) 15751–15759.Previous) [29] A. Rolle, P. Ruoussel, A. Rubbens, R.N. Vannier, Solid State Ionics. (2007) 1–14.Corrected) [29] N. Tarasova, I. Animitsa, T. Denisova, R. Nevmyvako, Solid State Ionics 275 (2015) 47–52. -
PublicationFabrication of phosphor in glass using waste glass for automotive lighting application( 2023)
;Choi, Seung-hee ;Kwon, Seok-bin ;Yoo, Junghyeon ;Na, Minyoung ;Kim, Bo-young ;Yoon, Ho-shin ;Park, Seounghyok ;Kang, Bongkyun ;Yoon, DaehoSong, YounghyunWith advancement of technology, requirements for light-emitting devices are increasing. Various types of packaging technologies have been suggested to improve the performance of light-emitting diode (LED). Among them, phosphor in glass (PiG) is attracting attention due to its manufactural facility and easily tunable characteristics. As PiG draws increasing attention, research on glass materials is also being actively conducted. However, studies about glass in the field of phosphor are mainly conducted on fabrication. Only a few studies about recycling have been reported. Thus, the objective of this study was to recycle waste glass discarded in other fields due to breakage and failure and use it to fabricate phosphor in glass. Cylindrical waste glass was pulverized into powder with an average size of 12 μm, mixed with a phosphor and sintered to be reborn as a phosphor in glass to broaden the recycling route for waste glass. -
PublicationGlass powder doping of nanocrystal-doped fibres: Challenges and results( 2022)
;Dorosz, Dominik ;Kochanowicz, Marcin ;Lesniak, Magdalena ;Müller, Robert ;Lorenz, Martin ;Kobelke, Jens ;Wondraczek, Katrin ;Valiente, Rafael ;Diego-Rucabado, Andrea ;Cano, Israel ;Aguado, Fernando ;Gluch, JürgenJäger, Matthias L.Incorporating new optical materials as nanocrystals into glass fibres for new functionalities has recently become a hot research topic. Our team (funded by the European FET Open project NCLAS) investigates the introduction of nanoscale laser crystallites into the core of optical fibres using the glass powder doping method. Active Y2O3:Pr3+ nanocrystals (NCs) were prepared via different synthesis methods, and structurally and spectroscopically characterized. After modification of technological parameters, the optimised NCs have been proposed as a luminescence centres to embed into germanate and silicate glass hosts. Glasses were analysed in terms of optical (transmission, refractive index matching to NCs) and thermal (thermal stability, viscosity, thermal expansion coefficient) parameters. Crystallisation issues during fibre drawing were particularly investigated. In a first step, glass powder-NCs mixing techniques and fibre preform preparation were developed. It was shown that temperature cycle profiles including dwell time and heating/cooling ramp rates influenced the glass-NCs properties and can lead to glass crystallisation or NCs dissolution. The sintering investigations pointed out the melting temperature limits to preserve active NCs in the glasses. In germanate glasses, Y2O3:Pr3+ dissolution was noticed at 800°C. In the case of the silicate glass compositions these regions vary from 700°C to 1050°C. The results allowed to select optical fibre drawing conditions performed by the powder-in-tube method. Their distribution uniformity is not yet sufficient, requiring further optimisation of the drawing kinetics.