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Author Frolov, A.S.; Callaert, C.; Batuk, M.; Hadermann, J.; Volykhov, A.A.; Sirotina, A.P.; Amati, M.; Gregoratti, L.; Yashina, L.V.
Title Nanoscale phase separation in the oxide layer at GeTe (111) surfaces Type A1 Journal article
Year 2022 Publication Nanoscale Abbreviated Journal Nanoscale
Volume 14 Issue 35 Pages 12918-12927
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract As a semiconductor ferroelectric, GeTe has become a focus of renewed attention due to the recent discovery of giant Rashba splitting. It already has a wide range of applications, from thermoelectricity to data storage. Its stability in ambient air, as well as the structure and properties of an oxide layer, define the processing media for device production and operation. Here, we studied a reaction between the GeTe (111) surface and molecular oxygen for crystals having solely inversion domains. We evaluated the reaction kinetics both ex situ and in situ using NAP XPS. The structure of the oxide layer is extensively discussed, where, according to HAADF-STEM and STEM-EDX, nanoscale phase separation of GeO2 and Te is observed, which is unusual for semiconductors. We believe that such behaviour is closely related to the ferroelectric properties and the domain structure of GeTe.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000847743300001 Publication Date 2022-08-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2040-3364; 2040-3372 ISBN Additional Links UA library record; WoS full record
Impact Factor 6.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:190665 Serial 7181
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Author Guo, A.; Bai, H.; Liang, Q.; Feng, L.; Su, X.; Van Tendeloo, G.; Wu, J.
Title Resistive switching in Ag₂Te semiconductor modulated by Ag+-ion diffusion and phase transition Type A1 Journal article
Year 2022 Publication Advanced Electronic Materials Abbreviated Journal Adv Electron Mater
Volume Issue Pages 2200850-2200858
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Memristors are considered to be the fourth circuit element and have great potential in areas like logic operations, information storage, and neuromorphic computing. The functional material in a memristor, which has a nonlinear resistance, is the key component to be developed. Herein, resistive switching is demonstrated and the structural evolutions in Ag2Te are examined under an external electric field. It is shown that the electroresistance effect is originating from an electronically triggered phase transition together with directional Ag+-ion diffusion. Using in situ transmission electron microscopy, the phase transition from the monoclinic alpha-Ag2Te into the face-centered cubic beta-Ag2Te, accompanied by a change in resistance, is directly observed. Diffusion of Ag+-ions modulates the localized density of Ag+-ion vacancies, leading to a change in electrical conductivity and influences the threshold voltage to trigger the phase transition. During the electric field-driven phase transition, the spontaneous and localized multiple polarizations from the low-symmetry alpha-Ag2Te (referring to an antiferroelectric structure) are vanishing in the cubic beta-Ag2Te (referring to a paraelectric structure). The abrupt resistance change of thin Ag2Te caused by the phase transition and modulated by the applied electric field demonstrates its great potential as functional material in volatile memory and memristors with a low-energy consumption.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000855728500001 Publication Date 2022-09-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2199-160x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.2 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.2
Call Number UA @ admin @ c:irua:190582 Serial 7203
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Author Morsdorf, L.; Kashiwar, A.; Kübel, C.; Tasan, C.C.
Title Carbon segregation and cementite precipitation at grain boundaries in quenched and tempered lath martensite Type A1 Journal article
Year 2023 Publication Materials science and engineering: part A: structural materials: properties, microstructure and processing Abbreviated Journal
Volume 862 Issue Pages 144369-21
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Tempering is widely applied to make carbon atoms beneficially rearrange in high strength steel microstructures after quenching; though the nano-scale interaction of carbon atoms with crystallographic defects is hard to experimentally observe. To improve, we investigate the redistribution of carbon atoms along martensite grain boundaries in a quenched and tempered low carbon steel. We observe the tempering-induced microstructural evolution by in-situ heating in a transmission electron microscope (TEM) and by compositional analysis through atom probe tomography (APT). Probe volumes for APT originate from a single martensite packet but in different tempering conditions, which is achieved via a sequential lift-out with in-between tempering treatments. The complementary use of TEM and APT provides crystallographic as well as chemical information on carbon segregation and subsequent carbide precipitation at martensite grain boundaries. The results show that the amount of carbon segregation to martensite grain boundaries is influenced by the boundary type, e.g. low-angle lath or high-angle block boundaries. Also, the growth behavior of cementite precipitates from grain boundary nucleation sites into neighboring martensite grains differs at low- and high-angle grain boundaries. This is due to the crystallographic constraints arising from the semi-coherent orientation relationship between cementite and adjacent martensite. We also show that slower quenching stabilizes thin retained austenite films between martensite grains because of enhanced carbon segregation during cooling. Finally, we demonstrate the effect of carbon redistribution along martensite grain boundaries on the mechanical properties. Here, we compare micro-scale Vickers hardness results from boundary-containing probe volumes to nanoindentation results from pure bulk martensite (boundary-free) probe volumes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000905165700001 Publication Date 2022-12-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-5093 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.4; 2023 IF: 3.094
Call Number UA @ admin @ c:irua:192279 Serial 7285
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Author Krishnamurthy, S.C.; Arseenko, M.; Kashiwar, A.; Dufour, P.; Marchal, Y.; Delahaye, J.; Idrissi, H.; Pardoen, T.; Mertens, A.; Simar, A.
Title Controlled precipitation in a new Al-Mg-Sc alloy for enhanced corrosion behavior while maintaining the mechanical performance Type A1 Journal article
Year 2023 Publication Materials characterization Abbreviated Journal
Volume 200 Issue Pages 112886-11
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The hot working of 5xxx series alloys with Mg ≥3.5 wt% is a concern due to the precipitation of β (Al3Mg2) phase at grain boundaries favoring Inter Granular Corrosion (IGC). The mechanical and corrosion properties of a new 5028-H116 Al-Mg-Sc alloy under various β precipitates distribution is analyzed by imposing different cooling rates from the hot forming temperature (i.e. 325 °C). The mechanical properties are maintained regardless of the heat treatment. However, the different nucleation sites and volume fractions of β precipitates for different cooling rates critically affect IGC. Controlled furnace cooling after the 325 °C heat treatment is ideal in 5028-H116 alloy to reduce susceptibility to IGC after sensitization.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000977059100001 Publication Date 2023-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.7; 2023 IF: 2.714
Call Number UA @ admin @ c:irua:195598 Serial 7291
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Author Hajizadeh, A.; Shahalizade, T.; Riahifar, R.; Yaghmaee, M.S.; Raissi, B.; Gholam, S.; Aghaei, A.; Rahimisheikh, S.; Ghazvini, A.S.
Title Electrophoretic deposition as a fabrication method for Li-ion battery electrodes and separators : a review Type A1 Journal article
Year 2022 Publication Journal of power sources Abbreviated Journal J Power Sources
Volume 535 Issue Pages 231448-26
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Electrophoretic Deposition (EPD) is one of the alternative methods to fabricate and enhance the performance of Li-ion batteries. It enables the fabrication of electrodes with outstanding qualities and different electrochemical properties by the great domination over various parameters. EPD facilitates the processing of electrodes by binder-free grafting of nanomaterials, such as graphene derivatives, carbon nanotube, and nanoparticles, into the battery electrodes. It also enables the assembly of the free-standing electrodes with 3D structure and provides possibilities, such as the fabrication of the electrodes with an oriented microstructure, even on 3D substrates to improve the energy or power density. In this review, after an introduction to EPD, the effect of EPD parameters on the properties of the prepared electrodes is reviewed. Then, EPD is compared with tape cast, and its advantages over the conventional method are evaluated. Also, employing the EPD method as an intermediate process is discussed. Finally, the application of EPD in the fabrication of separators is assessed, and the prospects for the future are described.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000913348500001 Publication Date 2022-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-7753 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.2 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 9.2
Call Number UA @ admin @ c:irua:194403 Serial 7303
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Author Zhang, Z.; Chen, X.; Shi, X.; Hu, Y.; Huang, J.; Liu, S.; Ren, Z.; Huang, H.; Han, G.; Van Tendeloo, G.; Tian, H.
Title Morphotropic phase boundary in pure perovskite lead titanate at room temperature Type A1 Journal article
Year 2022 Publication Materials Today Nano Abbreviated Journal
Volume 20 Issue Pages 100275-5
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract For many decades, great efforts have been devoted to pursue a large piezoelectric response by an intelligent design of morphotropic phase boundaries (MPB) in solid solutions, where tetragonal (T) and rhombohedral (R) structures coexist. For example, classical PbZrxTi1-xO3 and Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystals demonstrate a giant piezoelectric response near MPB. However, as the end member of these solids, perovskite-structured PbTiO3 always adopts the T phase at room temperature. Here, we report a pathway to create room temperature MPB in a single-phase PbTiO3. The uniaxial stress along the c-axis drives a T-R phase transition bridged by a monoclinic (M) phase, which facilitates a polarization rotation in the monodomain PbTiO3. Meanwhile, we demonstrate that the coexistence of T and R phases at room temperature can be achieved via an extremely mismatched heterointerface system. The uniaxial pressure is proved as an efficient way to break the inherent symmetry and able to substantially tailor the phase transition temperature Tc. These findings provide new insights into MPB, offering the opportunity to explore the giant piezoelectric response in single-phase materials. (c) 2022 Elsevier Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000906548600002 Publication Date 2022-10-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2588-8420 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.3 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 10.3
Call Number UA @ admin @ c:irua:193477 Serial 7324
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Author Yang, C.-Q.; Zhi, R.; Rothmann, M.U.; Xu, Y.-Y.; Li, L.-Q.; Hu, Z.-Y.; Pang, S.; Cheng, Y.-B.; Van Tendeloo, G.; Li, W.
Title Unveiling the intrinsic structure and intragrain defects of organic-inorganic hybrid perovskites by ultralow dose transmission electron microscopy Type A1 Journal article
Year 2023 Publication Advanced materials Abbreviated Journal
Volume Issue Pages 1-9
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Transmission electron microscopy (TEM) is a powerful tool for unveiling the structural, compositional, and electronic properties of organic-inorganic hybrid perovskites (OIHPs) at the atomic to micrometer length scales. However, the structural and compositional instability of OIHPs under electron beam radiation results in misunderstandings of the microscopic structure-property-performance relationship in OIHP devices. Here, ultralow dose TEM is utilized to identify the mechanism of the electron-beam-induced changes in OHIPs and clarify the cumulative electron dose thresholds (critical dose) of different commercially interesting state-of-the-art OIHPs, including methylammonium lead iodide (MAPbI(3)), formamidinium lead iodide (FAPbI(3)), FA(0.83)Cs(0.17)PbI(3), FA(0.15)Cs(0.85)PbI(3), and MAPb(0.5)Sn(0.5)I(3). The critical dose is related to the composition of the OIHPs, with FA(0.15)Cs(0.85)PbI(3) having the highest critical dose of approximate to 84 e angstrom(-2) and FA(0.83)Cs(0.17)PbI(3) having the lowest critical dose of approximate to 4.2 e angstrom(-2). The electron beam irradiation results in the formation of a superstructure with ordered I and FA vacancies along (c), as identified from the three major crystal axes in cubic FAPbI(3), (c), (c), and (c). The intragrain planar defects in FAPbI(3) are stable, while an obvious modification is observed in FA(0.83)Cs(0.17)PbI(3) under continuous electron beam exposure. This information can serve as a guide for ensuring a reliable understanding of the microstructure of OIHP optoelectronic devices by TEM.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000950461600001 Publication Date 2023-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 29.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 29.4; 2023 IF: 19.791
Call Number UA @ admin @ c:irua:195116 Serial 7349
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Author Kante, M.V.; Weber, M.L.; Ni, S.; van den Bosch, I.C.G.; van der Minne, E.; Heymann, L.; Falling, L.J.; Gauquelin, N.; Tsvetanova, M.; Cunha, D.M.; Koster, G.; Gunkel, F.; Nemsak, S.; Hahn, H.; Estrada, L.V.; Baeumer, C.
Title A high-entropy oxide as high-activity electrocatalyst for water oxidation Type A1 Journal article
Year 2023 Publication ACS nano Abbreviated Journal
Volume 17 Issue 6 Pages 5329-5339
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High-entropy materials are an emerging pathway in the development of high-activity (electro)catalysts because of the inherent tunability and coexistence of multiple potential active sites, which may lead to earth-abundant catalyst materials for energy-efficient electrochemical energy storage. In this report, we identify how the multication composition in high-entropy perovskite oxides (HEO) contributes to high catalytic activity for the oxygen evolution reaction (OER), i.e., the key kinetically limiting half-reaction in several electrochemical energy conversion technologies, including green hydrogen generation. We compare the activity of the (001) facet of LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3-delta with the parent compounds (single B-site in the ABO3 perovskite). While the single B-site perovskites roughly follow the expected volcano-type activity trends, the HEO clearly outperforms all of its parent compounds with 17 to 680 times higher currents at a fixed overpotential. As all samples were grown as an epitaxial layer, our results indicate an intrinsic composition-function relationship, avoiding the effects of complex geometries or unknown surface composition. In-depth X-ray photoemission studies reveal a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during the adsorption of reaction intermediates. The surprisingly high OER activity demonstrates that HEOs are a highly attractive, earth-abundant material class for high-activity OER electrocatalysts, possibly allowing the activity to be fine-tuned beyond the scaling limits of mono-or bimetallic oxides.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000953440900001 Publication Date 2023-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.1 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 17.1; 2023 IF: 13.942
Call Number UA @ admin @ c:irua:196097 Serial 7390
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Author Belik, A.A.; Morozov, V.A.; Deyneko, D.V.; Savon, A.E.; Baryshnikova, O.V.; Zhukovskaya, E.S.; Dorbakov, N.G.; Katsuya, Y.; Tanaka, M.; Stefanovich, S.Y.; Hadermann, J.; Lazoryak, B.I.
Title Antiferroelectric properties and site occupations ofR3+ cations in Ca8MgR(PO4)7 luminescent host materials Type A1 Journal article
Year 2017 Publication Journal of alloys and compounds Abbreviated Journal
Volume 699 Issue Pages 928-937
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ca8MgR(PO4)(7) = La, Pr, Nd, Sm-Lu, and Y) phosphates with a beta-Ca-3(PO4)(2) related structure were prepared by a standard solid-state method in air. Second-harmonic generation, differential scanning calorimetry, and dielectric measurements led to the conclusion that all Ca8MgR(PO4)(7) are centrosymmetric and go to another centrosymmetric phase in the course of a first-order antiferroelectric phase transition well above room temperature (RT). High-temperature electron diffraction showed that the symmetry changes from R (3) over barc to R (3) over barm during the phase transition. Structures of Ca8MgR(PO4)(7) at RT were refined by the Rietveld method in centrosymmetric space group R (3) over barc. Mg2+ cations occupy the M5 site; the occupancy of the M1 site by R3+ cations increases monotonically from 0.0389 for R = La to 0.1667 for R = Er-Lu, whereas the occupancy of the M3 site by R3+ cations decreases monotonically from 0.1278 for R = La to 0 for R = Er-Lu. In the case of R = Er-Lu, the M3 site is occupied only by Ca2+ cations. P1O(4) tetrahedra and cations at the M3 site are disordered in the R (3) over barc structure of Ca8MgEu(PO4)(7). Using synchrotron X-ray powder diffraction, we found that annealing conditions do not significantly affect the distribution of Ca2+ and Eu3+ cations between the structure positions of Ca8MgEu(PO4)(7). Luminescent properties of CasMgEu(PO4)(7) powder samples were investigated under near-ultraviolet (n-UV) light. Excitation spectra of CasMgEu(PO4)(7) show the strongest absorption at about 395 nm that matches with commercially available n-UV-emitting GaN-based LED chips. Emission spectra show an intense red emission due to the D-5(0) -> F-7(2) transition of Eu3+. (C) 2016 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000393727500129 Publication Date 2016-12-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:152665 Serial 7464
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Author Naberezhnyi, D.; Rumyantseva, M.; Filatova, D.; Batuk, M.; Hadermann, J.; Baranchikov, A.; Khmelevsky, N.; Aksenenko, A.; Konstantinova, E.; Gaskov, A.
Title Effects of Ag additive in low temperature CO detection with In2O3 based gas sensors Type A1 Journal article
Year 2018 Publication Nanomaterials Abbreviated Journal
Volume 8 Issue 10 Pages 801
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Nanocomposites In2O3/Ag obtained by ultraviolet (UV) photoreduction and impregnation methods were studied as materials for CO sensors operating in the temperature range 25-250 degrees C. Nanocrystalline In2O3 and In2O3/Ag nanocomposites were characterized by X-ray diffraction (XRD), single-point Brunauer-Emmet-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) with energy dispersive X-ray (EDX) mapping. The active surface sites were investigated using Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy and thermo-programmed reduction with hydrogen (TPR-H-2) method. Sensor measurements in the presence of 15 ppm CO demonstrated that UV treatment leads to a complete loss of In2O3 sensor sensitivity, while In2O3/Ag-UV nanocomposite synthesized by UV photoreduction demonstrates an increased sensor signal to CO at T < 200 degrees C. The observed high sensor response of the In2O3/Ag-UV nanocomposite at room temperature may be due to the realization of an additional mechanism of CO oxidation with participation of surface hydroxyl groups associated via hydrogen bonds.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000451174100057 Publication Date 2018-10-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-4991 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:156335 Serial 7842
Permanent link to this record
 

 
Author Yang, T.; Kong, Y.; Li, K.; Lu, Q.; Wang, Y.; Du, Y.; Schryvers, D.
Title Quasicrystalline clusters transformed from C14-MgZn₂ nanoprecipitates in Al alloys Type A1 Journal article
Year 2023 Publication Materials characterization Abbreviated Journal
Volume 199 Issue Pages 112772-112777
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Ultrafine faulty C14-MgZn2 Laves phase precipitates containing quasicrystalline clusters and demonstrating the formation of binary quasicrystalline precipitates with Penrose-like random-tiling were observed in the over-aged FCC matrix of a commercial 7N01 Al-Zn-Mg alloy, using high angle annular dark field scanning transmission electron microscopy. The evolution from C14-Laves phase to quasicrystalline clusters is illustrated, and five-fold symmetry can be found in both real and reciprocal spaces. Our findings reveal the possibility of quasicrystalline formation from Laves phase in a highly plastic metal matrix like Al and demonstrate the structural relationship between Laves phase and quasicrystals.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000954788800001 Publication Date 2023-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1044-5803 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.7; 2023 IF: 2.714
Call Number UA @ admin @ c:irua:196106 Serial 8446
Permanent link to this record
 

 
Author Dubrovinskaia, N.; Dubrovinsky, L.; Solopova, N.A.; Abakumov, A.; Turner, S.; Hanfland, M.; Bykova, E.; Bykov, M.; Prescher, C.; Prakapenka, V.B.; Petitgirard, S.; Chuvashova, I.; Gasharova, B.; Mathis, Y.-L.; Ershov, P.; Snigireva, I.; Snigirev, A.
Title Terapascal static pressure generation with ultrahigh yield strength nanodiamond Type A1 Journal article
Year 2016 Publication Science Advances Abbreviated Journal
Volume 2 Issue 7 Pages e1600341-12
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Studies of materials' properties at high and ultrahigh pressures lead to discoveries of unique physical and chemical phenomena and a deeper understanding of matter. In high-pressure research, an achievable static pressure limit is imposed by the strength of available strong materials and design of high-pressure devices. Using a high-pressure and high-temperature technique, we synthesized optically transparent microballs of bulk nanocrystalline diamond, which were found to have an exceptional yield strength (similar to 460 GPa at a confining pressure of similar to 70 GPa) due to the unique microstructure of bulk nanocrystalline diamond. We used the nanodiamond balls in a double-stage diamond anvil cell high-pressure device that allowed us to generate static pressures beyond 1 TPa, as demonstrated by synchrotron x-ray diffraction. Outstanding mechanical properties (strain-dependent elasticity, very high hardness, and unprecedented yield strength) make the nanodiamond balls a unique device for ultrahigh static pressure generation. Structurally isotropic, homogeneous, and made of a low-Z material, they are promising in the field of x-ray optical applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000381805300029 Publication Date 2016-07-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2375-2548 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:190527 Serial 8647
Permanent link to this record
 

 
Author Sasaki, S.; Giri, S.; Cassidy, S.J.; Dey, S.; Batuk, M.; Vandemeulebroucke, D.; Cibin, G.; Smith, R.I.; Holdship, P.; Grey, C.P.; Hadermann, J.; Clarke, S.J.
Title Anion redox as a means to derive layered manganese oxychalcogenides with exotic intergrowth structures Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal
Volume 14 Issue 1 Pages 2917-11
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Topochemistry enables step-by-step conversions of solid-state materials often leading to metastable structures that retain initial structural motifs. Recent advances in this field revealed many examples where relatively bulky anionic constituents were actively involved in redox reactions during (de)intercalation processes. Such reactions are often accompanied by anion-anion bond formation, which heralds possibilities to design novel structure types disparate from known precursors, in a controlled manner. Here we present the multistep conversion of layered oxychalcogenides Sr(2)MnO(2)Cu(1.5)Ch(2) (Ch=S, Se) into Cu-deintercalated phases where antifluorite type [Cu(1.5)Ch(2)](2.5-) slabs collapsed into two-dimensional arrays of chalcogen dimers. The collapse of the chalcogenide layers on deintercalation led to various stacking types of Sr(2)MnO(2)Ch(2) slabs, which formed polychalcogenide structures unattainable by conventional high-temperature syntheses. Anion-redox topochemistry is demonstrated to be of interest not only for electrochemical applications but also as a means to design complex layered architectures. Low temperature chemical transformations of solids using high-energy intermediates have enabled the synthesis of a new series of layered oxide chalcogenide containing oxidised chalcogenide dimers promising a new range of solids.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001024186000011 Publication Date 2023-05-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number UA @ admin @ c:irua:199281 Serial 8832
Permanent link to this record
 

 
Author Wang, Y.; Yuan, Y.; Liao, X.; Van Tendeloo, G.; Zhao, Y.; Sun, C.
Title Chip-based in situ TEM investigation of structural thermal instability in aged layered cathode Type A1 Journal article
Year 2023 Publication Nanoscale Advances Abbreviated Journal
Volume 5 Issue 16 Pages 4182-4190
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Thermally induced oxygen release is an intrinsic structural instability in layered cathodes, which causes thermal runaway issues and becomes increasingly critical with the continuous improvement in energy density. Furthermore, thermal runaway events always occur in electrochemically aged cathodes, where the coupling of the thermal and electrochemical effect remains elusive. Herein, we report the anomalous segregation of cobalt metal in an aged LiCoO2 cathode, which is attributed to the local exposure of the high-energy (100) surface of LiCoO2 and weak interface Co-O dangling bonds significantly promoting the diffusion of Co. The presence of the LCO-Co interface severely aggregated the oxygen release in the form of dramatic Co growth. A unique particle-to-particle oxygen release pathway was also found, starting from the isolated high reduction areas induced by the cycling heterogeneity. This study provides atomistic insight into the robust coupling between the intrinsic structural instability and electrochemical cycling.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001030149900001 Publication Date 2023-07-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2516-0230 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.7; 2023 IF: NA
Call Number UA @ admin @ c:irua:198281 Serial 8841
Permanent link to this record
 

 
Author Soltan, S.; Macke, S.; Ilse, S.E.; Pennycook, T.; Zhang, Z.L.; Christiani, G.; Benckiser, E.; Schuetz, G.; Goering, E.
Title Ferromagnetic order controlled by the magnetic interface of LaNiO3/La2/3Ca1/3MnO3 superlattices Type A1 Journal article
Year 2023 Publication Scientific reports Abbreviated Journal
Volume 13 Issue 1 Pages 1-9
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Interface engineering in complex oxide superlattices is a growing field, enabling manipulation of the exceptional properties of these materials, and also providing access to new phases and emergent physical phenomena. Here we demonstrate how interfacial interactions can induce a complex charge and spin structure in a bulk paramagnetic material. We investigate a superlattice (SLs) consisting of paramagnetic LaNiO3 (LNO) and highly spin-polarized ferromagnetic La2/3Ca1/3MnO3 (LCMO), grown on SrTiO3 (001) substrate. We observed emerging magnetism in LNO through an exchange bias mechanism at the interfaces in X-ray resonant magnetic reflectivity. We find non-symmetric interface induced magnetization profiles in LNO and LCMO which we relate to a periodic complex charge and spin superstructure. High resolution scanning transmission electron microscopy images reveal that the upper and lower interfaces exhibit no significant structural variations. The different long range magnetic order emerging in LNO layers demonstrates the enormous potential of interfacial reconstruction as a tool for tailored electronic properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000985158100013 Publication Date 2023-03-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.6 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 4.6; 2023 IF: 4.259
Call Number UA @ admin @ c:irua:197426 Serial 8867
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Author Ying, J.; Xiao, Y.; Chen, J.; Hu, Z.-Y.; Tian, G.; Van Tendeloo, G.; Zhang, Y.; Symes, M.D.D.; Janiak, C.; Yang, X.-Y.
Title Fractal design of hierarchical PtPd with enhanced exposed surface atoms for highly catalytic activity and stability Type A1 Journal article
Year 2023 Publication Nano letters Abbreviated Journal
Volume 23 Issue 16 Pages 7371-7378
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Hierarchicalassembly of arc-like fractal nanostructures not onlyhas its unique self-similarity feature for stability enhancement butalso possesses the structural advantages of highly exposed surface-activesites for activity enhancement, remaining a great challenge for high-performancemetallic nanocatalyst design. Herein, we report a facile strategyto synthesize a novel arc-like hierarchical fractal structure of PtPdbimetallic nanoparticles (h-PtPd) by using pyridinium-type ionic liquidsas the structure-directing agent. Growth mechanisms of the arc-likenanostructured PtPd nanoparticles have been fully studied, and precisecontrol of the particle sizes and pore sizes has been achieved. Dueto the structural features, such as size control by self-similaritygrowth of subunits, structural stability by nanofusion of subunits,and increased numbers of exposed active atoms by the curved homoepitaxialgrowth, h-PtPd displays outstanding electrocatalytic activity towardoxygen reduction reaction and excellent stability during hydrothermaltreatment and catalytic process.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001042181100001 Publication Date 2023-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.8 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 10.8; 2023 IF: 12.712
Call Number UA @ admin @ c:irua:198408 Serial 8870
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Author Yu, R.; Zeng, W.; Zhou, L.; Van Tendeloo, G.; Mai, L.; Yao, Z.; Wu, J.
Title Layer-by-layer delithiation during lattice collapse as the origin of planar gliding and microcracking in Ni-rich cathodes Type A1 Journal article
Year 2023 Publication Cell reports physical science Abbreviated Journal
Volume 4 Issue 7 Pages 101480-14
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract High-energy-density nickel (Ni)-rich cathode materials are used in commercial lithium (Li)-ion batteries for electric vehicles, but they suffer from severe structural degradation upon cycling. Planar gliding and microcracking are seeds for fatal mechanical fracture, but their origin remains unclear. Herein, we show that “layer-by -layer delithiation”is activated at high voltages during the charge process when the “lattice collapse”(a characteristic high-voltage lattice evolution in Ni-rich cathodes) occurs. Layer-by-layer deli-thiation is evidenced by direct observation of the consecutive lattice collapse using in situ scanning transmission electron micro-scopy (STEM). The collapsing of the lattice initiates in the expanded planes and consecutively extends to the whole crystal. Localized strain will be induced at lattice-collapsing interface where planar gliding and intragranular microcracks are generated to release this strain. Our study reveals that layer-by-layer delithia-tion during lattice collapse is the fundamental origin of the mechanical instability in single-crystalline Ni-rich cathodes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001048074500001 Publication Date 2023-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:198299 Serial 8893
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Author Gheysen, J.; Kashiwar, A.; Idrissi, H.; Villanova, J.; Simar, A.
Title Suppressing hydrogen blistering in a magnesium-rich healable laser powder bed fusion aluminum alloy analyzed by in-situ high resolution techniques Type A1 Journal article
Year 2023 Publication Materials & design Abbreviated Journal
Volume 231 Issue Pages 112024-11
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Hydrogen blistering, i.e. precipitation of supersaturated hydrogen at elevated temperatures, increases porosity during heat treatments in 4xxx series Al alloys manufactured by laser powder bed fusion (LPBF), as demonstrated by 3D X-ray nano-imaging in AlSi12. This paper proposes the design of a healable Al alloy to suppress hydrogen blistering and improve the damage management. The strategy consists of solute atoms diffusing towards nano-voids and precipitating on their surface, thereby filling the damage sites. A new healable Al alloy was thus developed and successfully manufactured by LPBF. 3D X-ray nano-imaging evidenced that the addition of Mg in 4xxx series Al alloys suppresses the hydrogen blistering. This is expectedly due to Mg in solid solution which increases the hydrogen solubility in the Al matrix and due to the healing of these hydrogen pores. Moreover, a significant healing of voids smaller than 500 nm diameter is observed. In-situ heating inside transmission electron microscopy pointed out that Al matrix diffuses inside the fractured Mg2Si particles, thereby demonstrating the healing ability of the new alloy. This has opened the doors to development of new healable Al alloys manufactured by LPBF as well as to new post-treatments to tailor mechanical properties and microstructure without hydrogen blistering.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001055174900001 Publication Date 2023-05-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.4 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 8.4; 2023 IF: 4.364
Call Number UA @ admin @ c:irua:196536 Serial 8939
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Author Cui, W.; Lin, W.; Lu, W.; Liu, C.; Gao, Z.; Ma, H.; Zhao, W.; Van Tendeloo, G.; Zhao, W.; Zhang, Q.; Sang, X.
Title Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps Type A1 Journal article
Year 2023 Publication Nature communications Abbreviated Journal
Volume 14 Issue 1 Pages 554-10
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te-6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials. Weak interlayer van der Waals (vdW) bonding has significant impact on the structure and properties of vdW layered materials. Here authors use in-situ aberration-corrected ADF-STEM for an atomistic insight into the cation diffusion in the vdW gaps and the etching of vdW surfaces at high temperatures.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001076227200001 Publication Date 2023-02-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 16.6 Times cited Open Access
Notes Approved Most recent IF: 16.6; 2023 IF: 12.124
Call Number UA @ admin @ c:irua:201342 Serial 9021
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Author Kashiwar, A.; Arseenko, M.; Simar, A.; Idrissi, H.
Title On the role of microstructural defects on precipitation, damage, and healing behavior in a novel Al-0.5Mg2Si alloy Type A1 Journal article
Year 2024 Publication Materials & design Abbreviated Journal
Volume 239 Issue Pages 112765-112769
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract A recently developed healable Al-Mg2Si designed by the programmed damage and repair (PDR) strategy is studied considering the role microstructural defects play on precipitation, damage, and healing. The alloy incorporates sacrificial Mg2Si particles that precipitate after friction stir processing (FSP). They act as damage localization sites and are healable based on the solid-state diffusion of Al-matrix. A combination of different transmission electron microscopy (TEM) imaging techniques enabled the visualization and quantification of various crystallographic defects and the spatial distribution of Mg2Si precipitates. Intragrain nucleation is found to be the dominant mechanism for precipitation during FSP whereas grain boundaries and subgrain boundaries mainly lead to coarsening of the precipitates. The statistical and spatial analyses of the damaged particles have shown particle fracture as the dominant damage mechanism which is strongly dependent on the size and aspect ratio of the particles whereas the damage was not found to depend on the location of the precipitates within the matrix. The damaged particles are associated with dislocations accumulated around them. The interplay of these dislocations is directly visualized during healing based on in situ TEM heating which revealed recovery in the matrix as an operative mechanism during the diffusion healing of the PDR alloy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001194110200001 Publication Date 2024-02-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0264-1275; 1873-4197 ISBN Additional Links UA library record; WoS full record
Impact Factor 8.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 8.4; 2024 IF: 4.364
Call Number UA @ admin @ c:irua:203298 Serial 9068
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Author Gao, Y.-J.; Jin, H.; Esteban, D.A.; Weng, B.; Saha, R.A.; Yang, M.-Q.; Bals, S.; Steele, J.A.; Huang, H.; Roeffaers, M.B.J.
Title 3D-cavity-confined CsPbBr₃ quantum dots for visible-light-driven photocatalytic C(sp³)-H bond activation Type A1 Journal article
Year 2024 Publication Carbon Energy Abbreviated Journal
Volume Issue Pages e559
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Metal halide perovskite (MHP) quantum dots (QDs) offer immense potential for several areas of photonics research due to their easy and low-cost fabrication and excellent optoelectronic properties. However, practical applications of MHP QDs are limited by their poor stability and, in particular, their tendency to aggregate. Here, we develop a two-step double-solvent strategy to grow and confine CsPbBr3 QDs within the three-dimensional (3D) cavities of a mesoporous SBA-16 silica scaffold (CsPbBr3@SBA-16). Strong confinement and separation of the MHP QDs lead to a relatively uniform size distribution, narrow luminescence, and good ambient stability over 2 months. In addition, the CsPbBr3@SBA-16 presents a high activity and stability for visible-light-driven photocatalytic toluene C(sp(3))-H bond activation to produce benzaldehyde with similar to 730 mu mol g(-1) h(-1) yield rate and near-unity selectivity. Similarly, the structural stability of CsPbBr3@SBA-16 QDs is superior to that of both pure CsPbBr3 QDs and those confined in MCM-41 with 1D channels.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001223583600001 Publication Date 2024-05-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2637-9368 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:206000 Serial 9133
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Author Yang, C.-Q.; Yin, Z.-W.; Li, W.; Cui, W.-J.; Zhou, X.-G.; Wang, L.-D.; Zhi, R.; Xu, Y.-Y.; Tao, Z.-W.; Sang, X.; Cheng, Y.-B.; Van Tendeloo, G.; Hu, Z.-Y.; Su, B.-L.
Title Atomically deciphering the phase segregation in mixed halide perovskite Type A1 Journal article
Year 2024 Publication Advanced functional materials Abbreviated Journal
Volume Issue Pages 1-10
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Mixed-halide perovskites show promising applications in tandem solar cells owing to their adjustable bandgap. One major obstacle to their commercialization is halide phase segregation, which results in large open-circuit voltage deficiency and J-V hysteresis. However, the ambiguous interplay between structural origin and phase segregation often results in aimless and unspecific optimization strategies for the device's performance and stability. An atomic scale is directly figured out the abundant Ruddlesden-Popper anti-phase boundaries (RP-APBs) within a CsPbIBr2 polycrystalline film and revealed that phase segregation predominantly occurs at RP-APB-enriched interfaces due to the defect-mediated lattice strain. By compensating their structural lead halide, such RP-APBs are eliminated, and the decreasing of strain can be observed, resulting in the suppression of halide phase segregation. The present work provides the deciphering to precisely regulate the perovskite atomic structure for achieving photo-stable mixed halide wide-bandgap perovskites of high-efficiency tandem solar cell commercial applications. The phase segregation in mixed halide perovskite film predominantly occurs at Ruddlesden-Popper anti-phase boundaries (RP-APBs)-enriched interfaces due to the defect-mediated lattice strain. The RP-APBs defects can be eliminated by compensating for their structural lead halide deficiency, resulting in the suppression of halide phase segregation. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001200673300001 Publication Date 2024-04-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record
Impact Factor 19 Times cited Open Access
Notes Approved Most recent IF: 19; 2024 IF: 12.124
Call Number UA @ admin @ c:irua:205509 Serial 9134
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Author Morad, V.; Stelmakh, A.; Svyrydenko, M.; Feld, L.G.; Boehme, S.C.; Aebli, M.; Affolter, J.; Kaul, C.J.; Schrenker, N.J.; Bals, S.; Sahin, Y.; Dirin, D.N.; Cherniukh, I.; Raino, G.; Baumketner, A.; Kovalenko, M.V.
Title Designer phospholipid capping ligands for soft metal halide nanocrystals Type A1 Journal article
Year 2024 Publication Nature Abbreviated Journal
Volume 626 Issue Pages 542-548
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The success of colloidal semiconductor nanocrystals (NCs) in science and optoelectronics is inextricable from their surfaces. The functionalization of lead halide perovskite NCs1-5 poses a formidable challenge because of their structural lability, unlike the well-established covalent ligand capping of conventional semiconductor NCs6,7. We posited that the vast and facile molecular engineering of phospholipids as zwitterionic surfactants can deliver highly customized surface chemistries for metal halide NCs. Molecular dynamics simulations implied that ligand-NC surface affinity is primarily governed by the structure of the zwitterionic head group, particularly by the geometric fitness of the anionic and cationic moieties into the surface lattice sites, as corroborated by the nuclear magnetic resonance and Fourier-transform infrared spectroscopy data. Lattice-matched primary-ammonium phospholipids enhance the structural and colloidal integrity of hybrid organic-inorganic lead halide perovskites (FAPbBr3 and MAPbBr3 (FA, formamidinium; MA, methylammonium)) and lead-free metal halide NCs. The molecular structure of the organic ligand tail governs the long-term colloidal stability and compatibility with solvents of diverse polarity, from hydrocarbons to acetone and alcohols. These NCs exhibit photoluminescence quantum yield of more than 96% in solution and solids and minimal photoluminescence intermittency at the single particle level with an average ON fraction as high as 94%, as well as bright and high-purity (about 95%) single-photon emission. Phospholipids enhance the structural and colloidal integrity of hybrid organic-inorganic lead halide perovskites and lead-free metal halide nanocrystals, which then exhibit enhanced robustness and optical properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001176943100001 Publication Date 2023-12-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836; 1476-4687 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 64.8 Times cited Open Access
Notes Approved Most recent IF: 64.8; 2024 IF: 40.137
Call Number UA @ admin @ c:irua:204796 Serial 9144
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Author Xu, H.; Li, H.; Gauquelin, N.; Chen, X.; Wu, W.-F.; Zhao, Y.; Si, L.; Tian, D.; Li, L.; Gan, Y.; Qi, S.; Li, M.; Hu, F.; Sun, J.; Jannis, D.; Yu, P.; Chen, G.; Zhong, Z.; Radovic, M.; Verbeeck, J.; Chen, Y.; Shen, B.
Title Giant tunability of Rashba splitting at cation-exchanged polar oxide interfaces by selective orbital hybridization Type A1 Journal article
Year 2024 Publication Advanced materials Abbreviated Journal
Volume Issue Pages
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract The 2D electron gas (2DEG) at oxide interfaces exhibits extraordinary properties, such as 2D superconductivity and ferromagnetism, coupled to strongly correlated electrons in narrow d-bands. In particular, 2DEGs in KTaO3 (KTO) with 5d t2g orbitals exhibit larger atomic spin-orbit coupling and crystal-facet-dependent superconductivity absent for 3d 2DEGs in SrTiO3 (STO). Herein, by tracing the interfacial chemistry, weak anti-localization magneto-transport behavior, and electronic structures of (001), (110), and (111) KTO 2DEGs, unambiguously cation exchange across KTO interfaces is discovered. Therefore, the origin of the 2DEGs at KTO-based interfaces is dramatically different from the electronic reconstruction observed at STO interfaces. More importantly, as the interface polarization grows with the higher order planes in the KTO case, the Rashba spin splitting becomes maximal for the superconducting (111) interfaces approximately twice that of the (001) interface. The larger Rashba spin splitting couples strongly to the asymmetric chiral texture of the orbital angular moment, and results mainly from the enhanced inter-orbital hopping of the t2g bands and more localized wave functions. This finding has profound implications for the search for topological superconductors, as well as the realization of efficient spin-charge interconversion for low-power spin-orbitronics based on (110) and (111) KTO interfaces. An unambiguous cation exchange is discovered across the interfaces of (001), (110), and (111) KTaO3 2D electron gases fabricated at room temperature. Remarkably, the (111) interfaces with the highest superconducting transition temperature also turn out to show the strongest electron-phonon interaction and the largest Rashba spin splitting. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001219658400001 Publication Date 2024-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0935-9648 ISBN Additional Links UA library record; WoS full record
Impact Factor 29.4 Times cited Open Access
Notes Approved Most recent IF: 29.4; 2024 IF: 19.791
Call Number UA @ admin @ c:irua:206037 Serial 9152
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Author Bampouli, A.; Goris, Q.; Hussain, M.N.; Louisnard, O.; Stefanidis, G.D.; Van Gerven, T.
Title Importance of design and operating parameters in a sonication system for viscous solutions : effects of input power, horn tip diameter and reactor capacity Type A1 Journal article
Year 2024 Publication Chemical engineering and processing Abbreviated Journal
Volume 198 Issue Pages 109715-12
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract This study investigates the distribution of ultrasound (US) energy in a batch system for solutions with viscosity ranging from 1 to approximately 3000 mPas. Sonication was performed using horn type configurations operating at 20-30 kHz and rated power capacity of 50 or 200 W. Two different tip diameters (3 or 7 mm) and two insertion depths (35 or 25 mm) within vessels of different sizes ( approximate to 60 or 130 ml) were utilized. Additionally, a special conical tip design was employed. For each experimental setup, the calorimetric efficiency was estimated, the cavitationally active regions were visualized using the sonochemiluminescence (SCL) method and bubble cluster formation inside the vessel was macroscopically observed using a high speed camera (HSC). In the viscosity range tested, the calorimetry results showed that the efficiency and continuous operation of the device depend on both the rated power and the horn tip diameter. The ratio between electrical and calorimetric power input remained consistently around 40 to 50% across the different configurations for water, but for the 123.2 mPas solution exhibited significant variation ranging from 40 to 85%. Moreover, the power density in the smaller reactor was found to be nearly double compared to the larger one. The SCL analysis showed multiple cavitationally active zones in all setups, and the zones intensity decreased considerably with increase of the solutions viscosity. The results for the cone tip were not conclusive, but can be used as the basis for further investigation. The current research highlights the importance of thoroughly understanding the impact of each design parameter, and of establishing characterization methodologies to assist in the future development of scaled-up, commercial applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001218630800001 Publication Date 2024-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0255-2701 ISBN Additional Links UA library record; WoS full record
Impact Factor 4.3 Times cited Open Access
Notes Approved Most recent IF: 4.3; 2024 IF: 2.234
Call Number UA @ admin @ c:irua:206003 Serial 9154
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Author Wang, G.; Xie, C.; Wang, H.; Li, Q.; Xia, F.; Zeng, W.; Peng, H.; Van Tendeloo, G.; Tan, G.; Tian, J.; Wu, J.
Title Mitigated oxygen loss in lithium-rich manganese-based cathode enabled by strong Zr-O affinity Type A1 Journal article
Year 2024 Publication Advanced functional materials Abbreviated Journal
Volume Issue Pages 2313672
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Oxygen loss is a serious problem of lithium-rich layered oxide (LLO) cathodes, as the high capacity of LLO relies on reversible oxygen redox. Oxygen release can occur at the surface leading to the formation of spinel or rock salt structures. Also, the lattice oxygen will usually become unstable after long cycling, which remains a major roadblock in the application of LLO. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in LLO due to the high affinity between Zr and O. A simple sol-gel method is used to dope Zr4+ into the LLOs to adjust the local electronic structure and inhibit the diffusion of oxygen anions to the surface during cycling. Compared with untreated LLOs, LLO-Zr cathodes exhibit a higher cycling stability, with 94% capacity retention after 100 cycles at 0.4 C, up to 223 mAh g-1 at 1 C, and 88% capacity retention after 300 cycles. Theoretical calculations show that due to the strong Zr-O covalent bonding, the formation energy of oxygen vacancies has effectively increased and the loss of lattice oxygen under high voltage can be suppressed. This study provides a simple method for developing high-capacity and cyclability Li-rich cathode materials for lithium-ion batteries. Oxygen release can occur at the cathode surface leading to the formation of spinel or rock salt structures. Here, it is shown that Zr doping is an effective strategy to retain lattice oxygen in lithium-rich layered oxides (LLO) due to the high affinity between Zr and O. LLO-Zr exhibit higher cycling stability, with 88% capacity retention after 300 cycles at 1 C. image
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001159843800001 Publication Date 2024-02-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616-301x ISBN Additional Links UA library record; WoS full record
Impact Factor 19 Times cited Open Access
Notes Approved Most recent IF: 19; 2024 IF: 12.124
Call Number UA @ admin @ c:irua:203812 Serial 9161
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Author Coulombier, M.; Baral, P.; Orekhov, A.; Dohmen, R.; Raskin, J.P.; Pardoen, T.; Cordier, P.; Idrissi, H.
Title On-chip very low strain rate rheology of amorphous olivine films Type A1 Journal article
Year 2024 Publication Acta materialia Abbreviated Journal
Volume 266 Issue Pages 119693-12
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1], a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle -ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension -on -chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10-12 s- 1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001170513400001 Publication Date 2024-01-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454 ISBN Additional Links UA library record; WoS full record
Impact Factor 9.4 Times cited Open Access
Notes Approved Most recent IF: 9.4; 2024 IF: 5.301
Call Number UA @ admin @ c:irua:204864 Serial 9163
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Author Joy, R.M.; Pobedinskas, P.; Bourgeois, E.; Chakraborty, T.; Goerlitz, J.; Herrmann, D.; Noel, C.; Heupel, J.; Jannis, D.; Gauquelin, N.; D'Haen, J.; Verbeeck, J.; Popov, C.; Houssiau, L.; Becher, C.; Nesladek, M.; Haenen, K.
Title Photoluminescence of germanium-vacancy centers in nanocrystalline diamond films : implications for quantum sensing applications Type A1 Journal article
Year 2024 Publication ACS applied nano materials Abbreviated Journal
Volume 7 Issue 4 Pages 3873-3884
Keywords (down) A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract Point defects in diamond, promising candidates for nanoscale pressure- and temperature-sensing applications, are potentially scalable in polycrystalline diamond fabricated using the microwave plasma-enhanced chemical vapor deposition (MW PE CVD) technique. However, this approach introduces residual stress in the diamond films, leading to variations in the characteristic zero phonon line (ZPL) of the point defect in diamond. Here, we report the effect of residual stress on germanium-vacancy (GeV) centers in MW PE CVD nanocrystalline diamond (NCD) films fabricated using single crystal Ge as the substrate and solid dopant source. GeV ensemble formation indicated by the zero phonon line (ZPL) at similar to 602 nm is confirmed by room temperature (RT) photoluminescence (PL) measurements. PL mapping results show spatial nonuniformity in GeV formation along with other defects, including silicon-vacancy centers in the diamond films. The residual stress in NCD results in shifts in the PL peak positions. By estimating a stress shift coefficient of (2.9 +/- 0.9) nm/GPa, the GeV PL peak position in the NCD film is determined to be between 598.7 and 603.2 nm. A larger ground state splitting due to the strain on a GeV-incorporated NCD pillar at a low temperature (10 K) is also reported. We also report the observation of intense ZPLs at RT that in some cases could be related to low Ge concentration and the surrounding crystalline environment. In addition, we also observe thicker microcrystalline diamond (MCD) films delaminate from the Ge substrate due to film residual stress and graphitic phase at the diamond/Ge substrate interface (confirmed by electron energy loss spectroscopy). Using this approach, a free-standing color center incorporated MCD film with dimensions up to 1 x 1 cm(2) is fabricated. Qualitative analysis using time-of-flight secondary ion mass spectroscopy reveals the presence of impurities, including Ge and silicon, in the MCD film. Our experimental results will provide insights into the scalability of GeV fabrication using the MW PE CVD technique and effectively implement NCD-based nanoscale-sensing applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001164609600001 Publication Date 2024-02-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0970 ISBN Additional Links UA library record; WoS full record
Impact Factor 5.9 Times cited Open Access
Notes Approved Most recent IF: 5.9; 2024 IF: NA
Call Number UA @ admin @ c:irua:204826 Serial 9164
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Author da Costa, L.F.; de Barros, A.G.; de Figueiredo Lopes Lucena, L.C.; de Figueiredo Lopes Lucena, A.E.
Title Asphalt mixture reinforced with banana fibres Type A1 Journal article
Year 2020 Publication Road Materials And Pavement Design Abbreviated Journal Road Mater Pavement
Volume Issue Pages
Keywords (down) A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Energy and Materials in Infrastructure and Buildings (EMIB)
Abstract Stone Matrix Asphalt (SMA) is a gap-graded mixture which requires high contents of asphalt binder. To prevent draindown, natural or synthetic fibres and polymer-modified asphalt binders are conventionally used in SMA. Banana agribusiness is one of the major sources of post-harvest residue in Brazil. Amongst those residues, fibres extracted from the pseudostem of the banana plant are resistant and used in diverse purposes. The present study assesses the incorporation of fibres from the pseudostem of the banana plant in an SMA mixture. The fibre contents and lengths capable to prevent binder draindown were evaluated from draindown tests. Mechanical properties of an SMA mixture stabilised with different banana fibre lengths were analysed through the tests of Marshall stability, modified Lottman, Indirect Tensile Strength and Cantabro. The results indicated that the fibres studied are a viable alternative for SMA, stabilising draindown and improving its mechanical performance, especially at the length of 20 mm.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000508499900001 Publication Date 2020-01-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1468-0629; 2164-7402 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited Open Access
Notes Approved Most recent IF: 3.7; 2020 IF: 1.401
Call Number UA @ admin @ c:irua:178727 Serial 7495
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Author Ferreira da Costa, L.; de Lucena, L.C.F.L.; de Lucena, A.E.F.L.; Grangeiro de Barros, A.
Title Use of Banana Fibers in SMA Mixtures Type A1 Journal article
Year 2020 Publication Journal Of Materials In Civil Engineering Abbreviated Journal J Mater Civil Eng
Volume 32 Issue 1 Pages 04019341
Keywords (down) A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT); Energy and Materials in Infrastructure and Buildings (EMIB)
Abstract Asphalt binder draindown is a potential issue related to stone matrix asphalt (SMA) mixtures. One convenient approach for reducing binder drainage is the use of fibers as stabilizing additives. This study assesses the feasibility of incorporating fibers from banana plants into an SMA mixture as a proposed use for residues from banana cultivation. We found the fiber content capable of preventing draindown and subsequently evaluated the influence of fiber length on the mechanical properties of an SMA mixture. Samples were prepared in a Superpave gyratory compactor with four different fiber lengths (5, 10, 15, and 20 mm) at a fixed content (0.3% by weight) and then compared to samples without fibers. Indirect tensile strength, resilient and dynamic modulus, flow number, and fatigue life tests were conducted. Overall, fibers improved the mechanical properties analyzed. These enhancements were more pronounced for the samples with 15- and 20-mm fibers. Thus, a smaller number of longer fibers was more beneficial to the fiber reinforcement of mixtures than a larger number of shorter fibers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000497709300014 Publication Date 2019-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0899-1561 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.2 Times cited Open Access
Notes Approved Most recent IF: 3.2; 2020 IF: 1.644
Call Number UA @ admin @ c:irua:178728 Serial 8719
Permanent link to this record